🕷️ Crawler Inspector

URL Lookup

Direct Parameter Lookup

Raw Queries and Responses

1. Shard Calculation

Query:

Response:

Calculated Shard: 194 (from laksa097)

2. Crawled Status Check

Query:

curl -X POST \
  'http://laksa194.int.ahrefs:8124/' \
  -H 'Content-Type: text/plain' \
  -H 'X-ClickHouse-Database: crawler3' \
  -H 'Authorization: Basic YXBpOg==' \
  -d 'SELECT getAhrefsURLFromUnparsed(src_unparsed) AS found_url, ifNull(toUnixTimestamp(download_stamp), 0) AS crawl_time, ifNull(toUnixTimestamp(props_url_first_seen), 0) AS first_indexed_time, download_http_code AS http_code, src_unparsed AS src_unparsed, src_root_hash AS src_root_hash, history_drop_reason AS history_drop_reason, meta_title AS meta_title, meta_descriptions AS meta_descriptions, attrs_boilerpipe_text AS attrs_boilerpipe_text, attrs_markdown AS attrs_markdown, attrs_readable_markdown AS attrs_readable_markdown, meta_canonical AS meta_canonical FROM crawler3.page_info_local FINAL PREWHERE (src_root_hash, src_unparsed) IN ((getAhrefsRootHashFromUnparsed(getAhrefsUnparsedNoserviceFromURL(\'https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy\')), getAhrefsUnparsedNoserviceFromURL(\'https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy\'))) FORMAT JSONEachRow'

Response:

{"found_url":"https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy","crawl_time":1776638903,"first_indexed_time":1712818680,"http_code":200,"src_unparsed":"org,uofmhealthsparrow!www,\/departments-conditions\/conditions\/shellfish-allergy s443","src_root_hash":"15754692202894961194","history_drop_reason":null,"meta_title":"Shellfish allergy | UM Health-Sparrow","meta_descriptions":["OverviewShellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails."],"attrs_boilerpipe_text":"Overview\nShellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails.\nShellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening.\nIf you think you have shellfish allergy, talk to your health care provider. Tests can help confirm the allergy so you can take steps to avoid future reactions.\nSymptoms\nShellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include:\nHives\nItchy, irritated skin\nNasal stuffiness (congestion)\nSwelling of the lips, face, tongue and throat, or other parts of the body\nWheezing or trouble breathing\nCoughing and choking or a tight feeling in the throat\nBelly (abdominal) pain, diarrhea, nausea or vomiting\nDizziness, lightheadedness or fainting\nAnaphylaxis\nAllergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to — and worsens quickly.\nAn anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal.\nAnaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include:\nA swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe\nCoughing, choking or wheezing with trouble breathing\nShock, with a severe drop in your blood pressure and a rapid or weak pulse\nSevere skin rash, hives, itching or swelling\nNausea, vomiting or diarrhea\nDizziness, lightheadedness or fainting\nWhen to see a doctor\nSeek emergency treatment if you develop signs or symptoms of anaphylaxis.\nSee a health care provider or allergy specialist if you have food allergy symptoms shortly after eating.\nCauses\nAll food allergies are caused by an immune system overreaction. Your immune system identifies a harmless substance as being harmful. This substance is called an allergen. In shellfish allergy, your immune system mistakenly identifies a certain protein in shellfish as harmful. Your immune system is how your body protects itself, so it produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the shellfish protein, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream. This causes a reaction that leads to the symptoms of an allergic reaction.\nTypes of shellfish\nThere are several types of shellfish, each containing different proteins:\nCrustaceans\ninclude crabs, lobster, crayfish, shrimp and prawn\nMollusks\ninclude squid, octopus, mussels, snails, clams, oysters, abalone and scallops\nAn allergy to crustaceans is the most common type. Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish.\nAn allergy to fish — such as salmon, tuna or catfish — is a different seafood allergy from an allergy to shellfish. Some people who are allergic to shellfish may still be able to eat fish, or they could be allergic to both. Your health care provider can help you determine what is safe to eat.\nRisk factors\nYou're at increased risk of developing shellfish allergy if allergies of any type are common in your family.\nThough people of any age can develop shellfish allergy, it's more common in adults. In fact, shellfish allergy is the most common food allergy in adults. Among adults, shellfish allergy is more common in women. Among children, shellfish allergy is more common in boys.\nComplications\nIn severe cases, shellfish allergy can lead to anaphylaxis, a dangerous allergic reaction that can be life-threatening.\nWhen you have shellfish allergy, you may be at increased risk of anaphylaxis if you have:\nAsthma\nAllergic reactions to very small amounts of shellfish (extreme sensitivity)\nHistory of food-induced anaphylaxis\nStrong family history of allergy\nAnaphylaxis is treated with an emergency injection of epinephrine (adrenaline). If you are at risk of having a severe allergic reaction to shellfish, you always should carry injectable epinephrine (Auvi-Q, EpiPen, others).\nPrevention\nIf you have shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people.\nAvoiding shellfish\nBe cautious when dining out.\nWhen dining at restaurants, always check to make sure that the pan, oil or utensils used for shellfish aren't also used to prepare other foods, creating cross-contamination. It might be necessary to avoid eating at seafood restaurants, where there's a high risk of cross-contamination.\nRead labels.\nCross-contamination can occur in stores where other food is processed or displayed near shellfish and during manufacturing. Shellfish may be in fish stock or seafood flavoring. Read food labels carefully.\nShellfish is not usually a hidden ingredient. Companies are required to label any product that contains crustacean shellfish or certain other foods that often cause allergic reactions. However, these regulations don't apply to mollusks.\nKeep your distance.\nYou may need to completely avoid places where shellfish are prepared or processed. Some people react after touching shellfish or inhaling steam from cooking shellfish.\nBe prepared\nIf you have shellfish allergy, talk with your health care provider about carrying emergency epinephrine and how to use it.\nConsider wearing a medical alert bracelet or necklace that lets others know you have a food allergy.\nIodine or radiocontrast dye\nOne thing you don't need to worry about is if you'll also be allergic to iodine or radiocontrast material that's used in some imaging tests. Even though shellfish contain small amounts of iodine, shellfish allergy is unrelated to the reactions some people have to radiocontrast material or iodine.\nDiagnosis\nTo find out if you have shellfish allergy, your health care provider will ask about your symptoms and do a physical exam to find or rule out other medical problems.\nA history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy. But the symptoms could also be caused by something else, such as food poisoning.\nAllergy testing is the only sure way to tell what's causing your symptoms, so your provider may recommend one or both of these tests:\nSkin prick test.\nSmall amounts of the proteins found in shellfish are pricked into skin on your arm or upper back. You're then watched for an allergic reaction. If you're allergic, you'll develop a raised bump (hive) at the test site on your skin. This typically takes about 15 to 20 minutes. Allergy specialists usually are best equipped to perform allergy skin tests.\nBlood test.\nA blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies.\nMedically supervised food challenges can be performed if the diagnosis still isn't clear after allergy testing.\nTreatment\nThe only sure way to prevent an allergic reaction to shellfish is to avoid shellfish. But despite your best efforts, you may come into contact with shellfish.\nIf you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection. Regularly check the expiration date on the packaging to make sure it's current.\nCarry injectable epinephrine (Auvi-Q, EpiPen, others) with you at all times. Epinephrine is typically given at the first sign of an allergic reaction. A second dose may be needed if symptoms recur. After you use epinephrine, seek emergency medical care, even if you start to feel better.\nPreparing for an appointment\nYou're likely to start by seeing your family health care provider. Or you may be referred directly to an allergy specialist.\nWhat you can do\nPrepare for your appointment by making a list of:\nSymptoms,\nincluding any that may seem unrelated to an allergy\nFamily history\nof allergies and asthma, including specific types of allergies if you know them\nMedications,\nvitamins, herbs or other supplements you're taking, and the dosages\nQuestions\nto ask your health care provider\nQuestions related to shellfish allergy include:\nAre my symptoms most likely due to an allergy?\nWill I need any allergy tests?\nShould I see an allergist?\nDo I need to carry epinephrine?\nAre there brochures or other educational materials I can have? What websites do you recommend?\nDon't hesitate to ask other questions, as well.\nWhat to expect from your doctor\nYour health care provider may ask you questions, such as:\nWhat symptoms are you having? How severe are they?\nWhen did you notice your symptoms?\nHave you reacted to shellfish in the past?\nWhat kind of shellfish did you eat?\nHow soon after eating shellfish did your symptoms occur?\nWhat other foods did you eat during your meal? Don't forget sauces, beverages and side dishes.\nDid others who dined with you have similar symptoms?\nIs there a history of allergy in your family?\nDo you have other allergies, such as hay fever?\nDo you have asthma or eczema (atopic dermatitis)?\nWhat you can do in the meantime\nAvoid eating or touching any type of shellfish while waiting for your appointment.","attrs_markdown":"[Skip to main content](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#main-content)\n\n## Utility\n- [Donate](https:\/\/secure.qgiv.com\/for\/spaheasys\/)\n- [Pay My Bill](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/pay-my-bill)\n- [Estimate Cost](https:\/\/mychart.sparrow.org\/MyChart\/GuestEstimates \"Price Estimator \")\n- [Careers](https:\/\/careers.sparrow.org\/)\n- [MySparrow Login](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/mysparrow)\n\n- [Medical Services](https:\/\/www.uofmhealthsparrow.org\/departments-conditions)\n- [Find a Doctor](https:\/\/www.uofmhealthsparrow.org\/find-a-doctor)\n- [Patient Resources](https:\/\/www.uofmhealthsparrow.org\/patient-resources)\n- [Locations](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services)\n- [Get Care Now](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now)\n\n## Main\n- [Medical Services](https:\/\/www.uofmhealthsparrow.org\/departments-conditions)\n  - FEATURED SERVICES\n  - [Cancer Care & Oncology](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/cancer-care-oncology)\n  - [Cardiovascular Care](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/cardiovascular-care)\n  - [Children's Center](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/pediatric-services)\n  - [Neurology & Neurosurgery](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/neuro-care-network)\n  - [Orthopedics & Sports Medicine](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/orthopedic-sports-medicine-services)\n  - [Primary Care](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/primary-care-practices)\n  - [Specialty Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/specialty-care-practices \"Specialty Care\")\n  - [Clinical Trials](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/um-health-sparrow-clinical-trials)\n  - MORE SERVICES\n  - [Obstetrics & Gynecology](https:\/\/www.uofmhealthsparrow.org\/departments-and-conditions\/all-departments-z\/obstetrics-gynecology-ob-gyn \"Obstetrics & Gynecology (OB\/GYN)\")\n  - [Laboratories](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/laboratories \"Laboratories\")\n  - [Medical Supply](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/services\/medical-supply \"Medical Supply\")\n  - [Radiology](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/radiology \"Radiology\")\n- [Find a Doctor](https:\/\/www.uofmhealthsparrow.org\/find-a-doctor)\n- [Patient Resources](https:\/\/www.uofmhealthsparrow.org\/patient-resources)\n  - [Prepare for Your Visit](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/prepare-your-visit \"Prepare for Your Visit\")\n  - [Labor & Delivery at Sparrow](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/labor-delivery)\n    - [Childbirth & Parenting](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/labor-delivery\/childbirth-and-parenting-support \"Expectant Parents Organization (EPO)\")\n    - [Delivery Services & Therapies](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/labor-delivery\/delivery-services-therapies \"Delivery Services & Therapies\")\n    - [High-Risk Pregnancy & Delivery](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/labor-delivery\/high-risk-pregnancy-delivery \"High-Risk Pregnancy & Delivery\")\n    - [Post Delivery Services & Therapies](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/labor-delivery\/lactation-breastfeeding-support \"Post Delivery Services & Therapies\")\n    - [Prenatal Information](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/labor-delivery\/prenatal-information \"Prenatal Information\")\n    - [Regional Neonatal Intensive Care Unit (RNICU)](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/pediatric-services\/regional-neonatal-intensive-care-unit \"Regional Neonatal Intensive Care Unit (RNICU)\")\n  - [Food & Nutrition at Sparrow](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/food-nutrition)\n  - [Financial Resources](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources)\n    - [Pay My Bill](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/pay-my-bill \"Pay My Bill\")\n    - [Billing & Insurance](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/billing-insurance \"Billing & Insurance\")\n    - [Estimates](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/estimate-your-cost \"Estimates\")\n    - [Financial Assistance](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/financial-assistance \"Financial Assistance\")\n    - [Financial Terms Glossary](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/financial-terms-glossary \"Financial Terms Glossary\")\n  - [Feedback on Sparrow](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/feedback-um-health-sparrow)\n  - [Palliative & Supportive Care](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/palliative-supportive-care)\n  - [Language Services](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/language-services)\n  - [Patient Rights & Safety](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/patient-rights-safety)\n    - [Patient Bill of Rights](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/patient-rights-safety\/patient-bill-rights \"Patient Bill of Rights\")\n    - [Release of Information FAQs](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/medical-records \"Release of Information FAQs\")\n  - [Visitor Resources](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/visitor-resources)\n    - [Lodging for Visitors](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/visitor-resources\/lodging-visitors \"Lodging for Visitors\")\n    - [Ronald McDonald House](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/childrens-center-pediatric-services\/ronald-mcdonald-house \"Ronald McDonald House\")\n    - [Visiting Hours](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/visitor-resources\/visiting-hours \"Visiting Hours\")\n- [Locations](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services)\n  - [Emergency Rooms (ERs)](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/emergency-rooms)\n  - [Same Day & Urgent Care Centers](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now)\n    - [Urgent Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now\/university-michigan-sparrow-urgent-care \"Urgent Care\")\n    - [Virtual Health](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/virtual-health \"Virtual Health\")\n    - [Walk-In Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now\/walk-care \"Walk-In Care\")\n  - [Hospitals](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals)\n    - [Sparrow Hospital](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/lansing \"Sparrow Hospital\")\n    - [Sparrow Hospital St. Lawrence](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/st-lawrence \"Sparrow Hospital St. Lawrence\")\n    - [Sparrow Carson Hospital](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/carson \"Sparrow Carson Hospital\")\n    - [Sparrow Clinton Hospital](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/clinton \"Sparrow Clinton Hospital\")\n    - [Sparrow Eaton Hospital](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/eaton \"Sparrow Eaton Hospital\")\n    - [Sparrow Ionia Hospital](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/ionia \"Sparrow Ionia Hospital\")\n    - [Sparrow Specialty Hospital](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/um-health-sparrow-hospitals\/specialty-hospital \"Sparrow Specialty Hospital\")\n  - [Virtual Health](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/virtual-health)\n  - [Services](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/services)\n    - [Home Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/services\/home-care \"Home Care\")\n    - [Hospice Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/services\/hospice-care \"Hospice Care\")\n    - [Laboratories](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/laboratories \"Laboratories\")\n    - [Medical Supply](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/services\/medical-supply \"Medical Supply\")\n    - [Pet Therapy Program](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/childrens-center-pediatric-services\/pet-therapy-program \"Pet Therapy Program\")\n    - [Pharmacies](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/services\/pharmacies \"Pharmacies\")\n    - [Radiology](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/radiology \"Radiology\")\n    - [Rehabilitation](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/rehabilitation \"Rehabilitation\")\n  - [Primary Care Practices](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/primary-care-practices)\n  - [Specialty Care Practices](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/specialty-care-practices)\n  - [AL!VE](https:\/\/www.myalive.com\/)\n- [Events](https:\/\/www.uofmhealthsparrow.org\/eventcalendar)\n- [Get Care Now](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now)\n\n## Utility\n- [Donate](https:\/\/secure.qgiv.com\/for\/spaheasys\/)\n- [Pay My Bill](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/pay-my-bill)\n- [Estimate Cost](https:\/\/mychart.sparrow.org\/MyChart\/GuestEstimates \"Price Estimator \")\n- [Careers](https:\/\/careers.sparrow.org\/)\n- [MySparrow Login](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/mysparrow)\n\n## Breadcrumb\n- [Home](https:\/\/www.uofmhealthsparrow.org\/)\n- [Departments & Conditions](https:\/\/www.uofmhealthsparrow.org\/departments-conditions)\n- [Conditions](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions)\n- Shellfish Allergy\n# Shellfish allergy\n\n- [Overview](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#overview)\n- [Symptoms](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#symptoms)\n- [Causes](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#causes)\n- [Risk factors](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#risk-factors)\n- [Complications](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#complications)\n- [Prevention](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#prevention)\n- [Diagnosis](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#diagnosis)\n- [Treatment](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#treatment)\n- [Preparing for an appointment](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/shellfish-allergy#preparing-for-an-appointment-)\n\n## Overview\nShellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails.\n\nShellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening.\n\nIf you think you have shellfish allergy, talk to your health care provider. Tests can help confirm the allergy so you can take steps to avoid future reactions.\n\n## Symptoms\nShellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include:\n\n- Hives\n- Itchy, irritated skin\n- Nasal stuffiness (congestion)\n- Swelling of the lips, face, tongue and throat, or other parts of the body\n- Wheezing or trouble breathing\n- Coughing and choking or a tight feeling in the throat\n- Belly (abdominal) pain, diarrhea, nausea or vomiting\n- Dizziness, lightheadedness or fainting\n### Anaphylaxis\nAllergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to — and worsens quickly.\n\nAn anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal.\n\nAnaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include:\n\n- A swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe\n- Coughing, choking or wheezing with trouble breathing\n- Shock, with a severe drop in your blood pressure and a rapid or weak pulse\n- Severe skin rash, hives, itching or swelling\n- Nausea, vomiting or diarrhea\n- Dizziness, lightheadedness or fainting\n### When to see a doctor\nSeek emergency treatment if you develop signs or symptoms of anaphylaxis.\n\nSee a health care provider or allergy specialist if you have food allergy symptoms shortly after eating.\n\n## Causes\nAll food allergies are caused by an immune system overreaction. Your immune system identifies a harmless substance as being harmful. This substance is called an allergen. In shellfish allergy, your immune system mistakenly identifies a certain protein in shellfish as harmful. Your immune system is how your body protects itself, so it produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the shellfish protein, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream. This causes a reaction that leads to the symptoms of an allergic reaction.\n\n### Types of shellfish\nThere are several types of shellfish, each containing different proteins:\n\n- **Crustaceans** include crabs, lobster, crayfish, shrimp and prawn\n- **Mollusks** include squid, octopus, mussels, snails, clams, oysters, abalone and scallops\n\nAn allergy to crustaceans is the most common type. Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish.\n\nAn allergy to fish — such as salmon, tuna or catfish — is a different seafood allergy from an allergy to shellfish. Some people who are allergic to shellfish may still be able to eat fish, or they could be allergic to both. Your health care provider can help you determine what is safe to eat.\n\n## Risk factors\nYou're at increased risk of developing shellfish allergy if allergies of any type are common in your family.\n\nThough people of any age can develop shellfish allergy, it's more common in adults. In fact, shellfish allergy is the most common food allergy in adults. Among adults, shellfish allergy is more common in women. Among children, shellfish allergy is more common in boys.\n\n## Complications\nIn severe cases, shellfish allergy can lead to anaphylaxis, a dangerous allergic reaction that can be life-threatening.\n\nWhen you have shellfish allergy, you may be at increased risk of anaphylaxis if you have:\n\n- Asthma\n- Allergic reactions to very small amounts of shellfish (extreme sensitivity)\n- History of food-induced anaphylaxis\n- Strong family history of allergy\n\nAnaphylaxis is treated with an emergency injection of epinephrine (adrenaline). If you are at risk of having a severe allergic reaction to shellfish, you always should carry injectable epinephrine (Auvi-Q, EpiPen, others).\n\n## Prevention\nIf you have shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people.\n\n### Avoiding shellfish\n- **Be cautious when dining out.** When dining at restaurants, always check to make sure that the pan, oil or utensils used for shellfish aren't also used to prepare other foods, creating cross-contamination. It might be necessary to avoid eating at seafood restaurants, where there's a high risk of cross-contamination.\n- **Read labels.** Cross-contamination can occur in stores where other food is processed or displayed near shellfish and during manufacturing. Shellfish may be in fish stock or seafood flavoring. Read food labels carefully.\n  Shellfish is not usually a hidden ingredient. Companies are required to label any product that contains crustacean shellfish or certain other foods that often cause allergic reactions. However, these regulations don't apply to mollusks.\n- **Keep your distance.** You may need to completely avoid places where shellfish are prepared or processed. Some people react after touching shellfish or inhaling steam from cooking shellfish.\n### Be prepared\nIf you have shellfish allergy, talk with your health care provider about carrying emergency epinephrine and how to use it.\n\nConsider wearing a medical alert bracelet or necklace that lets others know you have a food allergy.\n\n### Iodine or radiocontrast dye\nOne thing you don't need to worry about is if you'll also be allergic to iodine or radiocontrast material that's used in some imaging tests. Even though shellfish contain small amounts of iodine, shellfish allergy is unrelated to the reactions some people have to radiocontrast material or iodine.\n\n## Diagnosis\nTo find out if you have shellfish allergy, your health care provider will ask about your symptoms and do a physical exam to find or rule out other medical problems.\n\nA history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy. But the symptoms could also be caused by something else, such as food poisoning.\n\nAllergy testing is the only sure way to tell what's causing your symptoms, so your provider may recommend one or both of these tests:\n\n- **Skin prick test.** Small amounts of the proteins found in shellfish are pricked into skin on your arm or upper back. You're then watched for an allergic reaction. If you're allergic, you'll develop a raised bump (hive) at the test site on your skin. This typically takes about 15 to 20 minutes. Allergy specialists usually are best equipped to perform allergy skin tests.\n- **Blood test.** A blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies.\n\nMedically supervised food challenges can be performed if the diagnosis still isn't clear after allergy testing.\n\n![Skin surface showing a positive reaction to allergy test](https:\/\/www.uofmhealthsparrow.org\/sites\/default\/files\/mayo-api\/popup\/d\/DS00174_%20DS00339_%20DS00773_%20DS01067_%20MY00131_IM01607_aa7_dimethu_jpg.jpg)\n\n## Treatment\nThe only sure way to prevent an allergic reaction to shellfish is to avoid shellfish. But despite your best efforts, you may come into contact with shellfish.\n\nIf you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection. Regularly check the expiration date on the packaging to make sure it's current.\n\nCarry injectable epinephrine (Auvi-Q, EpiPen, others) with you at all times. Epinephrine is typically given at the first sign of an allergic reaction. A second dose may be needed if symptoms recur. After you use epinephrine, seek emergency medical care, even if you start to feel better.\n\n## Preparing for an appointment\nYou're likely to start by seeing your family health care provider. Or you may be referred directly to an allergy specialist.\n\n### What you can do\nPrepare for your appointment by making a list of:\n\n- **Symptoms,** including any that may seem unrelated to an allergy\n- **Family history** of allergies and asthma, including specific types of allergies if you know them\n- **Medications,** vitamins, herbs or other supplements you're taking, and the dosages\n- **Questions** to ask your health care provider\n\nQuestions related to shellfish allergy include:\n\n- Are my symptoms most likely due to an allergy?\n- Will I need any allergy tests?\n- Should I see an allergist?\n- Do I need to carry epinephrine?\n- Are there brochures or other educational materials I can have? What websites do you recommend?\n\nDon't hesitate to ask other questions, as well.\n\n### What to expect from your doctor\nYour health care provider may ask you questions, such as:\n\n- What symptoms are you having? How severe are they?\n- When did you notice your symptoms?\n- Have you reacted to shellfish in the past?\n- What kind of shellfish did you eat?\n- How soon after eating shellfish did your symptoms occur?\n- What other foods did you eat during your meal? Don't forget sauces, beverages and side dishes.\n- Did others who dined with you have similar symptoms?\n- Is there a history of allergy in your family?\n- Do you have other allergies, such as hay fever?\n- Do you have asthma or eczema (atopic dermatitis)?\n### What you can do in the meantime\nAvoid eating or touching any type of shellfish while waiting for your appointment.\n\n***\nContent From Mayo Clinic Updated: 07\/01\/2024    \n  © 1998-2026 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved.  [Terms of Use](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/conditions\/mayo-clinic-health-library-terms-use)\n\n[Find costs for the most common procedures, or contact our Estimates team by clicking here to visit MySparrow](https:\/\/mychart.sparrow.org\/MyChart\/GuestEstimates\/)\n\nConnect With Us\n\n## Footer Social Media\n- [Facebook](https:\/\/www.facebook.com\/UniversityofMichiganHealthSparrow\/)\n- [Linkedin](https:\/\/www.linkedin.com\/company\/university-of-michigan-health-sparrow\/)\n- [Youtube](https:\/\/www.youtube.com\/channel\/UCq-sL-ZAZakVsxFyxzdTIhA)\n- [Twitter](https:\/\/twitter.com\/UMHealthSparrow)\n- [Instagram](https:\/\/www.instagram.com\/umhealthsparrow\/)\n- [Email](https:\/\/www.uofmhealthsparrow.org\/cdn-cgi\/l\/email-protection#2f464149405d424e5b4640416f5a42475c5f4e5d5d405801405d48)\n\n[![Logo](https:\/\/www.uofmhealthsparrow.org\/sites\/default\/files\/styles\/scale_to_max_width_1920\/public\/2024-03\/logo.png?itok=SUkMmGGZ)](https:\/\/www.uofmhealthsparrow.org\/)\n\n## Footer Column 2\n- [Medical Services](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments)\n- [Find a Doctor](https:\/\/www.uofmhealthsparrow.org\/find-a-doctor)\n- [Patient Resources](https:\/\/www.uofmhealthsparrow.org\/patient-resources)\n- [Locations](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services)\n- [Contact Us](https:\/\/www.uofmhealthsparrow.org\/um-health-sparrow-community-health\/about-um-health-sparrow\/contact-us \"Contact Us\")\n\n## Footer Column 3\n- [Careers](https:\/\/careers.sparrow.org\/)\n- [Sparrow & Community Health](https:\/\/www.uofmhealthsparrow.org\/um-health-sparrow-community-health)\n- [Primary Care](https:\/\/www.uofmhealthsparrow.org\/departments-conditions\/all-departments\/primary-care-practices)\n- [Emergency](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/emergency-rooms)\n- [Price Transparency](https:\/\/www.uofmhealthsparrow.org\/patient-resources\/financial-resources\/standard-charges \"Price Transparency and Standard Charges\")\n\n## Footer Column 4\n- [Urgent Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now\/university-michigan-sparrow-urgent-care)\n- [Walk-in Care](https:\/\/www.uofmhealthsparrow.org\/our-hospitals-services\/get-care-now\/walk-care)\n- [Physician's Health Plan](https:\/\/www.uofmhealthplan.org\/)\n- [For Healthcare Professionals](https:\/\/www.uofmhealthsparrow.org\/healthcare-professionals)\n- [Event Calendar](https:\/\/www.uofmhealthsparrow.org\/eventcalendar \"UM Health-Sparrow Events\")\n\n## Footer Bottom\n- © 2026 University of Michigan Health-Sparrow. - All rights reserved.\n- [Legal & Policies](https:\/\/www.uofmhealthsparrow.org\/legal-policies)\n- [Nondiscrimination, Accessibility & Language Services](https:\/\/www.uofmhealthsparrow.org\/accessibility)\n- [Privacy Policy](https:\/\/www.uofmhealthsparrow.org\/privacy-policy)\n- [Sitemap](https:\/\/www.uofmhealthsparrow.org\/sitemap)\n- [Terms of Use](https:\/\/www.uofmhealthsparrow.org\/home\/terms-use)\n\n**Unsupported Browser\\!** This website will offer limited functionality in this browser. We only support the recent versions of major browsers like Chrome, Firefox, Safari, and Edge.\n\n×","attrs_readable_markdown":"## Overview\nShellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails.\n\nShellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening.\n\nIf you think you have shellfish allergy, talk to your health care provider. Tests can help confirm the allergy so you can take steps to avoid future reactions.\n\n## Symptoms\nShellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include:\n\n- Hives\n- Itchy, irritated skin\n- Nasal stuffiness (congestion)\n- Swelling of the lips, face, tongue and throat, or other parts of the body\n- Wheezing or trouble breathing\n- Coughing and choking or a tight feeling in the throat\n- Belly (abdominal) pain, diarrhea, nausea or vomiting\n- Dizziness, lightheadedness or fainting\n### Anaphylaxis\nAllergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to — and worsens quickly.\n\nAn anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal.\n\nAnaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include:\n\n- A swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe\n- Coughing, choking or wheezing with trouble breathing\n- Shock, with a severe drop in your blood pressure and a rapid or weak pulse\n- Severe skin rash, hives, itching or swelling\n- Nausea, vomiting or diarrhea\n- Dizziness, lightheadedness or fainting\n### When to see a doctor\nSeek emergency treatment if you develop signs or symptoms of anaphylaxis.\n\nSee a health care provider or allergy specialist if you have food allergy symptoms shortly after eating.\n\n## Causes\nAll food allergies are caused by an immune system overreaction. Your immune system identifies a harmless substance as being harmful. This substance is called an allergen. In shellfish allergy, your immune system mistakenly identifies a certain protein in shellfish as harmful. Your immune system is how your body protects itself, so it produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the shellfish protein, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream. This causes a reaction that leads to the symptoms of an allergic reaction.\n\n### Types of shellfish\nThere are several types of shellfish, each containing different proteins:\n\n- **Crustaceans** include crabs, lobster, crayfish, shrimp and prawn\n- **Mollusks** include squid, octopus, mussels, snails, clams, oysters, abalone and scallops\n\nAn allergy to crustaceans is the most common type. Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish.\n\nAn allergy to fish — such as salmon, tuna or catfish — is a different seafood allergy from an allergy to shellfish. Some people who are allergic to shellfish may still be able to eat fish, or they could be allergic to both. Your health care provider can help you determine what is safe to eat.\n\n## Risk factors\nYou're at increased risk of developing shellfish allergy if allergies of any type are common in your family.\n\nThough people of any age can develop shellfish allergy, it's more common in adults. In fact, shellfish allergy is the most common food allergy in adults. Among adults, shellfish allergy is more common in women. Among children, shellfish allergy is more common in boys.\n\n## Complications\nIn severe cases, shellfish allergy can lead to anaphylaxis, a dangerous allergic reaction that can be life-threatening.\n\nWhen you have shellfish allergy, you may be at increased risk of anaphylaxis if you have:\n\n- Asthma\n- Allergic reactions to very small amounts of shellfish (extreme sensitivity)\n- History of food-induced anaphylaxis\n- Strong family history of allergy\n\nAnaphylaxis is treated with an emergency injection of epinephrine (adrenaline). If you are at risk of having a severe allergic reaction to shellfish, you always should carry injectable epinephrine (Auvi-Q, EpiPen, others).\n\n## Prevention\nIf you have shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people.\n\n### Avoiding shellfish\n- **Be cautious when dining out.** When dining at restaurants, always check to make sure that the pan, oil or utensils used for shellfish aren't also used to prepare other foods, creating cross-contamination. It might be necessary to avoid eating at seafood restaurants, where there's a high risk of cross-contamination.\n- **Read labels.** Cross-contamination can occur in stores where other food is processed or displayed near shellfish and during manufacturing. Shellfish may be in fish stock or seafood flavoring. Read food labels carefully.\n  Shellfish is not usually a hidden ingredient. Companies are required to label any product that contains crustacean shellfish or certain other foods that often cause allergic reactions. However, these regulations don't apply to mollusks.\n- **Keep your distance.** You may need to completely avoid places where shellfish are prepared or processed. Some people react after touching shellfish or inhaling steam from cooking shellfish.\n### Be prepared\nIf you have shellfish allergy, talk with your health care provider about carrying emergency epinephrine and how to use it.\n\nConsider wearing a medical alert bracelet or necklace that lets others know you have a food allergy.\n\n### Iodine or radiocontrast dye\nOne thing you don't need to worry about is if you'll also be allergic to iodine or radiocontrast material that's used in some imaging tests. Even though shellfish contain small amounts of iodine, shellfish allergy is unrelated to the reactions some people have to radiocontrast material or iodine.\n\n## Diagnosis\nTo find out if you have shellfish allergy, your health care provider will ask about your symptoms and do a physical exam to find or rule out other medical problems.\n\nA history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy. But the symptoms could also be caused by something else, such as food poisoning.\n\nAllergy testing is the only sure way to tell what's causing your symptoms, so your provider may recommend one or both of these tests:\n\n- **Skin prick test.** Small amounts of the proteins found in shellfish are pricked into skin on your arm or upper back. You're then watched for an allergic reaction. If you're allergic, you'll develop a raised bump (hive) at the test site on your skin. This typically takes about 15 to 20 minutes. Allergy specialists usually are best equipped to perform allergy skin tests.\n- **Blood test.** A blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies.\n\nMedically supervised food challenges can be performed if the diagnosis still isn't clear after allergy testing.\n\n![Skin surface showing a positive reaction to allergy test](https:\/\/www.uofmhealthsparrow.org\/sites\/default\/files\/mayo-api\/popup\/d\/DS00174_%20DS00339_%20DS00773_%20DS01067_%20MY00131_IM01607_aa7_dimethu_jpg.jpg)\n\n## Treatment\nThe only sure way to prevent an allergic reaction to shellfish is to avoid shellfish. But despite your best efforts, you may come into contact with shellfish.\n\nIf you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection. Regularly check the expiration date on the packaging to make sure it's current.\n\nCarry injectable epinephrine (Auvi-Q, EpiPen, others) with you at all times. Epinephrine is typically given at the first sign of an allergic reaction. A second dose may be needed if symptoms recur. After you use epinephrine, seek emergency medical care, even if you start to feel better.\n\n## Preparing for an appointment\nYou're likely to start by seeing your family health care provider. Or you may be referred directly to an allergy specialist.\n\n### What you can do\nPrepare for your appointment by making a list of:\n\n- **Symptoms,** including any that may seem unrelated to an allergy\n- **Family history** of allergies and asthma, including specific types of allergies if you know them\n- **Medications,** vitamins, herbs or other supplements you're taking, and the dosages\n- **Questions** to ask your health care provider\n\nQuestions related to shellfish allergy include:\n\n- Are my symptoms most likely due to an allergy?\n- Will I need any allergy tests?\n- Should I see an allergist?\n- Do I need to carry epinephrine?\n- Are there brochures or other educational materials I can have? What websites do you recommend?\n\nDon't hesitate to ask other questions, as well.\n\n### What to expect from your doctor\nYour health care provider may ask you questions, such as:\n\n- What symptoms are you having? How severe are they?\n- When did you notice your symptoms?\n- Have you reacted to shellfish in the past?\n- What kind of shellfish did you eat?\n- How soon after eating shellfish did your symptoms occur?\n- What other foods did you eat during your meal? Don't forget sauces, beverages and side dishes.\n- Did others who dined with you have similar symptoms?\n- Is there a history of allergy in your family?\n- Do you have other allergies, such as hay fever?\n- Do you have asthma or eczema (atopic dermatitis)?\n### What you can do in the meantime\nAvoid eating or touching any type of shellfish while waiting for your appointment.","meta_canonical":null}

3. Robots.txt Check

Query:

Response:

4. Spam/Ban Check

Query:

Response:

5. Seen Status Check

ℹ️ Skipped - page is already crawled

📄

INDEXABLE

✅

CRAWLED

1 day ago

🤖

ROBOTS ALLOWED

Page Info Filters

Filter	Status	Condition	Details
HTTP status	PASS	`download_http_code = 200`	HTTP 200
Age cutoff	PASS	`download_stamp > now() - 6 MONTH`	0 months ago
History drop	PASS	`isNull(history_drop_reason)`	No drop reason
Spam/ban	PASS	`fh_dont_index != 1 AND ml_spam_score = 0`	ml_spam_score=0
Canonical	PASS	`meta_canonical IS NULL OR = '' OR = src_unparsed`	Not set

Page Details

Property	Value
URL	https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy
Last Crawled	2026-04-19 22:48:23 (1 day ago)
First Indexed	2024-04-11 06:58:00 (2 years ago)
HTTP Status Code	200
Meta Title	Shellfish allergy \| UM Health-Sparrow
Meta Description	OverviewShellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails.
Meta Canonical	null
Boilerpipe Text	Overview Shellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails. Shellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening. If you think you have shellfish allergy, talk to your health care provider. Tests can help confirm the allergy so you can take steps to avoid future reactions. Symptoms Shellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include: Hives Itchy, irritated skin Nasal stuffiness (congestion) Swelling of the lips, face, tongue and throat, or other parts of the body Wheezing or trouble breathing Coughing and choking or a tight feeling in the throat Belly (abdominal) pain, diarrhea, nausea or vomiting Dizziness, lightheadedness or fainting Anaphylaxis Allergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to — and worsens quickly. An anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal. Anaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include: A swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe Coughing, choking or wheezing with trouble breathing Shock, with a severe drop in your blood pressure and a rapid or weak pulse Severe skin rash, hives, itching or swelling Nausea, vomiting or diarrhea Dizziness, lightheadedness or fainting When to see a doctor Seek emergency treatment if you develop signs or symptoms of anaphylaxis. See a health care provider or allergy specialist if you have food allergy symptoms shortly after eating. Causes All food allergies are caused by an immune system overreaction. Your immune system identifies a harmless substance as being harmful. This substance is called an allergen. In shellfish allergy, your immune system mistakenly identifies a certain protein in shellfish as harmful. Your immune system is how your body protects itself, so it produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the shellfish protein, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream. This causes a reaction that leads to the symptoms of an allergic reaction. Types of shellfish There are several types of shellfish, each containing different proteins: Crustaceans include crabs, lobster, crayfish, shrimp and prawn Mollusks include squid, octopus, mussels, snails, clams, oysters, abalone and scallops An allergy to crustaceans is the most common type. Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish. An allergy to fish — such as salmon, tuna or catfish — is a different seafood allergy from an allergy to shellfish. Some people who are allergic to shellfish may still be able to eat fish, or they could be allergic to both. Your health care provider can help you determine what is safe to eat. Risk factors You're at increased risk of developing shellfish allergy if allergies of any type are common in your family. Though people of any age can develop shellfish allergy, it's more common in adults. In fact, shellfish allergy is the most common food allergy in adults. Among adults, shellfish allergy is more common in women. Among children, shellfish allergy is more common in boys. Complications In severe cases, shellfish allergy can lead to anaphylaxis, a dangerous allergic reaction that can be life-threatening. When you have shellfish allergy, you may be at increased risk of anaphylaxis if you have: Asthma Allergic reactions to very small amounts of shellfish (extreme sensitivity) History of food-induced anaphylaxis Strong family history of allergy Anaphylaxis is treated with an emergency injection of epinephrine (adrenaline). If you are at risk of having a severe allergic reaction to shellfish, you always should carry injectable epinephrine (Auvi-Q, EpiPen, others). Prevention If you have shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people. Avoiding shellfish Be cautious when dining out. When dining at restaurants, always check to make sure that the pan, oil or utensils used for shellfish aren't also used to prepare other foods, creating cross-contamination. It might be necessary to avoid eating at seafood restaurants, where there's a high risk of cross-contamination. Read labels. Cross-contamination can occur in stores where other food is processed or displayed near shellfish and during manufacturing. Shellfish may be in fish stock or seafood flavoring. Read food labels carefully. Shellfish is not usually a hidden ingredient. Companies are required to label any product that contains crustacean shellfish or certain other foods that often cause allergic reactions. However, these regulations don't apply to mollusks. Keep your distance. You may need to completely avoid places where shellfish are prepared or processed. Some people react after touching shellfish or inhaling steam from cooking shellfish. Be prepared If you have shellfish allergy, talk with your health care provider about carrying emergency epinephrine and how to use it. Consider wearing a medical alert bracelet or necklace that lets others know you have a food allergy. Iodine or radiocontrast dye One thing you don't need to worry about is if you'll also be allergic to iodine or radiocontrast material that's used in some imaging tests. Even though shellfish contain small amounts of iodine, shellfish allergy is unrelated to the reactions some people have to radiocontrast material or iodine. Diagnosis To find out if you have shellfish allergy, your health care provider will ask about your symptoms and do a physical exam to find or rule out other medical problems. A history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy. But the symptoms could also be caused by something else, such as food poisoning. Allergy testing is the only sure way to tell what's causing your symptoms, so your provider may recommend one or both of these tests: Skin prick test. Small amounts of the proteins found in shellfish are pricked into skin on your arm or upper back. You're then watched for an allergic reaction. If you're allergic, you'll develop a raised bump (hive) at the test site on your skin. This typically takes about 15 to 20 minutes. Allergy specialists usually are best equipped to perform allergy skin tests. Blood test. A blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies. Medically supervised food challenges can be performed if the diagnosis still isn't clear after allergy testing. Treatment The only sure way to prevent an allergic reaction to shellfish is to avoid shellfish. But despite your best efforts, you may come into contact with shellfish. If you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection. Regularly check the expiration date on the packaging to make sure it's current. Carry injectable epinephrine (Auvi-Q, EpiPen, others) with you at all times. Epinephrine is typically given at the first sign of an allergic reaction. A second dose may be needed if symptoms recur. After you use epinephrine, seek emergency medical care, even if you start to feel better. Preparing for an appointment You're likely to start by seeing your family health care provider. Or you may be referred directly to an allergy specialist. What you can do Prepare for your appointment by making a list of: Symptoms, including any that may seem unrelated to an allergy Family history of allergies and asthma, including specific types of allergies if you know them Medications, vitamins, herbs or other supplements you're taking, and the dosages Questions to ask your health care provider Questions related to shellfish allergy include: Are my symptoms most likely due to an allergy? Will I need any allergy tests? Should I see an allergist? Do I need to carry epinephrine? Are there brochures or other educational materials I can have? What websites do you recommend? Don't hesitate to ask other questions, as well. What to expect from your doctor Your health care provider may ask you questions, such as: What symptoms are you having? How severe are they? When did you notice your symptoms? Have you reacted to shellfish in the past? What kind of shellfish did you eat? How soon after eating shellfish did your symptoms occur? What other foods did you eat during your meal? Don't forget sauces, beverages and side dishes. Did others who dined with you have similar symptoms? Is there a history of allergy in your family? Do you have other allergies, such as hay fever? Do you have asthma or eczema (atopic dermatitis)? What you can do in the meantime Avoid eating or touching any type of shellfish while waiting for your appointment.
Markdown	[Skip to main content](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#main-content) ## Utility - [Donate](https://secure.qgiv.com/for/spaheasys/) - [Pay My Bill](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/pay-my-bill) - [Estimate Cost](https://mychart.sparrow.org/MyChart/GuestEstimates "Price Estimator ") - [Careers](https://careers.sparrow.org/) - [MySparrow Login](https://www.uofmhealthsparrow.org/patient-resources/mysparrow) - [Medical Services](https://www.uofmhealthsparrow.org/departments-conditions) - [Find a Doctor](https://www.uofmhealthsparrow.org/find-a-doctor) - [Patient Resources](https://www.uofmhealthsparrow.org/patient-resources) - [Locations](https://www.uofmhealthsparrow.org/our-hospitals-services) - [Get Care Now](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now) ## Main - [Medical Services](https://www.uofmhealthsparrow.org/departments-conditions) - FEATURED SERVICES - [Cancer Care & Oncology](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/cancer-care-oncology) - [Cardiovascular Care](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/cardiovascular-care) - [Children's Center](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/pediatric-services) - [Neurology & Neurosurgery](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/neuro-care-network) - [Orthopedics & Sports Medicine](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/orthopedic-sports-medicine-services) - [Primary Care](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/primary-care-practices) - [Specialty Care](https://www.uofmhealthsparrow.org/our-hospitals-services/specialty-care-practices "Specialty Care") - [Clinical Trials](https://www.uofmhealthsparrow.org/departments-conditions/um-health-sparrow-clinical-trials) - MORE SERVICES - [Obstetrics & Gynecology](https://www.uofmhealthsparrow.org/departments-and-conditions/all-departments-z/obstetrics-gynecology-ob-gyn "Obstetrics & Gynecology (OB/GYN)") - [Laboratories](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/laboratories "Laboratories") - [Medical Supply](https://www.uofmhealthsparrow.org/our-hospitals-services/services/medical-supply "Medical Supply") - [Radiology](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/radiology "Radiology") - [Find a Doctor](https://www.uofmhealthsparrow.org/find-a-doctor) - [Patient Resources](https://www.uofmhealthsparrow.org/patient-resources) - [Prepare for Your Visit](https://www.uofmhealthsparrow.org/patient-resources/prepare-your-visit "Prepare for Your Visit") - [Labor & Delivery at Sparrow](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/labor-delivery) - [Childbirth & Parenting](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/labor-delivery/childbirth-and-parenting-support "Expectant Parents Organization (EPO)") - [Delivery Services & Therapies](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/labor-delivery/delivery-services-therapies "Delivery Services & Therapies") - [High-Risk Pregnancy & Delivery](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/labor-delivery/high-risk-pregnancy-delivery "High-Risk Pregnancy & Delivery") - [Post Delivery Services & Therapies](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/labor-delivery/lactation-breastfeeding-support "Post Delivery Services & Therapies") - [Prenatal Information](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/labor-delivery/prenatal-information "Prenatal Information") - [Regional Neonatal Intensive Care Unit (RNICU)](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/pediatric-services/regional-neonatal-intensive-care-unit "Regional Neonatal Intensive Care Unit (RNICU)") - [Food & Nutrition at Sparrow](https://www.uofmhealthsparrow.org/patient-resources/food-nutrition) - [Financial Resources](https://www.uofmhealthsparrow.org/patient-resources/financial-resources) - [Pay My Bill](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/pay-my-bill "Pay My Bill") - [Billing & Insurance](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/billing-insurance "Billing & Insurance") - [Estimates](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/estimate-your-cost "Estimates") - [Financial Assistance](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/financial-assistance "Financial Assistance") - [Financial Terms Glossary](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/financial-terms-glossary "Financial Terms Glossary") - [Feedback on Sparrow](https://www.uofmhealthsparrow.org/patient-resources/feedback-um-health-sparrow) - [Palliative & Supportive Care](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/palliative-supportive-care) - [Language Services](https://www.uofmhealthsparrow.org/patient-resources/language-services) - [Patient Rights & Safety](https://www.uofmhealthsparrow.org/patient-resources/patient-rights-safety) - [Patient Bill of Rights](https://www.uofmhealthsparrow.org/patient-resources/patient-rights-safety/patient-bill-rights "Patient Bill of Rights") - [Release of Information FAQs](https://www.uofmhealthsparrow.org/patient-resources/medical-records "Release of Information FAQs") - [Visitor Resources](https://www.uofmhealthsparrow.org/patient-resources/visitor-resources) - [Lodging for Visitors](https://www.uofmhealthsparrow.org/patient-resources/visitor-resources/lodging-visitors "Lodging for Visitors") - [Ronald McDonald House](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/childrens-center-pediatric-services/ronald-mcdonald-house "Ronald McDonald House") - [Visiting Hours](https://www.uofmhealthsparrow.org/patient-resources/visitor-resources/visiting-hours "Visiting Hours") - [Locations](https://www.uofmhealthsparrow.org/our-hospitals-services) - [Emergency Rooms (ERs)](https://www.uofmhealthsparrow.org/our-hospitals-services/emergency-rooms) - [Same Day & Urgent Care Centers](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now) - [Urgent Care](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now/university-michigan-sparrow-urgent-care "Urgent Care") - [Virtual Health](https://www.uofmhealthsparrow.org/our-hospitals-services/virtual-health "Virtual Health") - [Walk-In Care](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now/walk-care "Walk-In Care") - [Hospitals](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals) - [Sparrow Hospital](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/lansing "Sparrow Hospital") - [Sparrow Hospital St. Lawrence](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/st-lawrence "Sparrow Hospital St. Lawrence") - [Sparrow Carson Hospital](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/carson "Sparrow Carson Hospital") - [Sparrow Clinton Hospital](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/clinton "Sparrow Clinton Hospital") - [Sparrow Eaton Hospital](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/eaton "Sparrow Eaton Hospital") - [Sparrow Ionia Hospital](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/ionia "Sparrow Ionia Hospital") - [Sparrow Specialty Hospital](https://www.uofmhealthsparrow.org/our-hospitals-services/um-health-sparrow-hospitals/specialty-hospital "Sparrow Specialty Hospital") - [Virtual Health](https://www.uofmhealthsparrow.org/our-hospitals-services/virtual-health) - [Services](https://www.uofmhealthsparrow.org/our-hospitals-services/services) - [Home Care](https://www.uofmhealthsparrow.org/our-hospitals-services/services/home-care "Home Care") - [Hospice Care](https://www.uofmhealthsparrow.org/our-hospitals-services/services/hospice-care "Hospice Care") - [Laboratories](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/laboratories "Laboratories") - [Medical Supply](https://www.uofmhealthsparrow.org/our-hospitals-services/services/medical-supply "Medical Supply") - [Pet Therapy Program](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/childrens-center-pediatric-services/pet-therapy-program "Pet Therapy Program") - [Pharmacies](https://www.uofmhealthsparrow.org/our-hospitals-services/services/pharmacies "Pharmacies") - [Radiology](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/radiology "Radiology") - [Rehabilitation](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/rehabilitation "Rehabilitation") - [Primary Care Practices](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/primary-care-practices) - [Specialty Care Practices](https://www.uofmhealthsparrow.org/our-hospitals-services/specialty-care-practices) - [AL!VE](https://www.myalive.com/) - [Events](https://www.uofmhealthsparrow.org/eventcalendar) - [Get Care Now](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now) ## Utility - [Donate](https://secure.qgiv.com/for/spaheasys/) - [Pay My Bill](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/pay-my-bill) - [Estimate Cost](https://mychart.sparrow.org/MyChart/GuestEstimates "Price Estimator ") - [Careers](https://careers.sparrow.org/) - [MySparrow Login](https://www.uofmhealthsparrow.org/patient-resources/mysparrow) ## Breadcrumb - [Home](https://www.uofmhealthsparrow.org/) - [Departments & Conditions](https://www.uofmhealthsparrow.org/departments-conditions) - [Conditions](https://www.uofmhealthsparrow.org/departments-conditions/conditions) - Shellfish Allergy # Shellfish allergy - [Overview](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#overview) - [Symptoms](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#symptoms) - [Causes](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#causes) - [Risk factors](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#risk-factors) - [Complications](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#complications) - [Prevention](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#prevention) - [Diagnosis](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#diagnosis) - [Treatment](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#treatment) - [Preparing for an appointment](https://www.uofmhealthsparrow.org/departments-conditions/conditions/shellfish-allergy#preparing-for-an-appointment-) ## Overview Shellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails. Shellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening. If you think you have shellfish allergy, talk to your health care provider. Tests can help confirm the allergy so you can take steps to avoid future reactions. ## Symptoms Shellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include: - Hives - Itchy, irritated skin - Nasal stuffiness (congestion) - Swelling of the lips, face, tongue and throat, or other parts of the body - Wheezing or trouble breathing - Coughing and choking or a tight feeling in the throat - Belly (abdominal) pain, diarrhea, nausea or vomiting - Dizziness, lightheadedness or fainting ### Anaphylaxis Allergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to — and worsens quickly. An anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal. Anaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include: - A swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe - Coughing, choking or wheezing with trouble breathing - Shock, with a severe drop in your blood pressure and a rapid or weak pulse - Severe skin rash, hives, itching or swelling - Nausea, vomiting or diarrhea - Dizziness, lightheadedness or fainting ### When to see a doctor Seek emergency treatment if you develop signs or symptoms of anaphylaxis. See a health care provider or allergy specialist if you have food allergy symptoms shortly after eating. ## Causes All food allergies are caused by an immune system overreaction. Your immune system identifies a harmless substance as being harmful. This substance is called an allergen. In shellfish allergy, your immune system mistakenly identifies a certain protein in shellfish as harmful. Your immune system is how your body protects itself, so it produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the shellfish protein, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream. This causes a reaction that leads to the symptoms of an allergic reaction. ### Types of shellfish There are several types of shellfish, each containing different proteins: - Crustaceans include crabs, lobster, crayfish, shrimp and prawn - Mollusks include squid, octopus, mussels, snails, clams, oysters, abalone and scallops An allergy to crustaceans is the most common type. Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish. An allergy to fish — such as salmon, tuna or catfish — is a different seafood allergy from an allergy to shellfish. Some people who are allergic to shellfish may still be able to eat fish, or they could be allergic to both. Your health care provider can help you determine what is safe to eat. ## Risk factors You're at increased risk of developing shellfish allergy if allergies of any type are common in your family. Though people of any age can develop shellfish allergy, it's more common in adults. In fact, shellfish allergy is the most common food allergy in adults. Among adults, shellfish allergy is more common in women. Among children, shellfish allergy is more common in boys. ## Complications In severe cases, shellfish allergy can lead to anaphylaxis, a dangerous allergic reaction that can be life-threatening. When you have shellfish allergy, you may be at increased risk of anaphylaxis if you have: - Asthma - Allergic reactions to very small amounts of shellfish (extreme sensitivity) - History of food-induced anaphylaxis - Strong family history of allergy Anaphylaxis is treated with an emergency injection of epinephrine (adrenaline). If you are at risk of having a severe allergic reaction to shellfish, you always should carry injectable epinephrine (Auvi-Q, EpiPen, others). ## Prevention If you have shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people. ### Avoiding shellfish - Be cautious when dining out. When dining at restaurants, always check to make sure that the pan, oil or utensils used for shellfish aren't also used to prepare other foods, creating cross-contamination. It might be necessary to avoid eating at seafood restaurants, where there's a high risk of cross-contamination. - Read labels. Cross-contamination can occur in stores where other food is processed or displayed near shellfish and during manufacturing. Shellfish may be in fish stock or seafood flavoring. Read food labels carefully. Shellfish is not usually a hidden ingredient. Companies are required to label any product that contains crustacean shellfish or certain other foods that often cause allergic reactions. However, these regulations don't apply to mollusks. - Keep your distance. You may need to completely avoid places where shellfish are prepared or processed. Some people react after touching shellfish or inhaling steam from cooking shellfish. ### Be prepared If you have shellfish allergy, talk with your health care provider about carrying emergency epinephrine and how to use it. Consider wearing a medical alert bracelet or necklace that lets others know you have a food allergy. ### Iodine or radiocontrast dye One thing you don't need to worry about is if you'll also be allergic to iodine or radiocontrast material that's used in some imaging tests. Even though shellfish contain small amounts of iodine, shellfish allergy is unrelated to the reactions some people have to radiocontrast material or iodine. ## Diagnosis To find out if you have shellfish allergy, your health care provider will ask about your symptoms and do a physical exam to find or rule out other medical problems. A history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy. But the symptoms could also be caused by something else, such as food poisoning. Allergy testing is the only sure way to tell what's causing your symptoms, so your provider may recommend one or both of these tests: - Skin prick test. Small amounts of the proteins found in shellfish are pricked into skin on your arm or upper back. You're then watched for an allergic reaction. If you're allergic, you'll develop a raised bump (hive) at the test site on your skin. This typically takes about 15 to 20 minutes. Allergy specialists usually are best equipped to perform allergy skin tests. - Blood test. A blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies. Medically supervised food challenges can be performed if the diagnosis still isn't clear after allergy testing. ![Skin surface showing a positive reaction to allergy test](https://www.uofmhealthsparrow.org/sites/default/files/mayo-api/popup/d/DS00174_%20DS00339_%20DS00773_%20DS01067_%20MY00131_IM01607_aa7_dimethu_jpg.jpg) ## Treatment The only sure way to prevent an allergic reaction to shellfish is to avoid shellfish. But despite your best efforts, you may come into contact with shellfish. If you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection. Regularly check the expiration date on the packaging to make sure it's current. Carry injectable epinephrine (Auvi-Q, EpiPen, others) with you at all times. Epinephrine is typically given at the first sign of an allergic reaction. A second dose may be needed if symptoms recur. After you use epinephrine, seek emergency medical care, even if you start to feel better. ## Preparing for an appointment You're likely to start by seeing your family health care provider. Or you may be referred directly to an allergy specialist. ### What you can do Prepare for your appointment by making a list of: - Symptoms, including any that may seem unrelated to an allergy - Family history of allergies and asthma, including specific types of allergies if you know them - Medications, vitamins, herbs or other supplements you're taking, and the dosages - Questions to ask your health care provider Questions related to shellfish allergy include: - Are my symptoms most likely due to an allergy? - Will I need any allergy tests? - Should I see an allergist? - Do I need to carry epinephrine? - Are there brochures or other educational materials I can have? What websites do you recommend? Don't hesitate to ask other questions, as well. ### What to expect from your doctor Your health care provider may ask you questions, such as: - What symptoms are you having? How severe are they? - When did you notice your symptoms? - Have you reacted to shellfish in the past? - What kind of shellfish did you eat? - How soon after eating shellfish did your symptoms occur? - What other foods did you eat during your meal? Don't forget sauces, beverages and side dishes. - Did others who dined with you have similar symptoms? - Is there a history of allergy in your family? - Do you have other allergies, such as hay fever? - Do you have asthma or eczema (atopic dermatitis)? ### What you can do in the meantime Avoid eating or touching any type of shellfish while waiting for your appointment. * Content From Mayo Clinic Updated: 07/01/2024 © 1998-2026 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. [Terms of Use](https://www.uofmhealthsparrow.org/departments-conditions/conditions/mayo-clinic-health-library-terms-use) [Find costs for the most common procedures, or contact our Estimates team by clicking here to visit MySparrow](https://mychart.sparrow.org/MyChart/GuestEstimates/) Connect With Us ## Footer Social Media - [Facebook](https://www.facebook.com/UniversityofMichiganHealthSparrow/) - [Linkedin](https://www.linkedin.com/company/university-of-michigan-health-sparrow/) - [Youtube](https://www.youtube.com/channel/UCq-sL-ZAZakVsxFyxzdTIhA) - [Twitter](https://twitter.com/UMHealthSparrow) - [Instagram](https://www.instagram.com/umhealthsparrow/) - [Email](https://www.uofmhealthsparrow.org/cdn-cgi/l/email-protection#2f464149405d424e5b4640416f5a42475c5f4e5d5d405801405d48) [![Logo](https://www.uofmhealthsparrow.org/sites/default/files/styles/scale_to_max_width_1920/public/2024-03/logo.png?itok=SUkMmGGZ)](https://www.uofmhealthsparrow.org/) ## Footer Column 2 - [Medical Services](https://www.uofmhealthsparrow.org/departments-conditions/all-departments) - [Find a Doctor](https://www.uofmhealthsparrow.org/find-a-doctor) - [Patient Resources](https://www.uofmhealthsparrow.org/patient-resources) - [Locations](https://www.uofmhealthsparrow.org/our-hospitals-services) - [Contact Us](https://www.uofmhealthsparrow.org/um-health-sparrow-community-health/about-um-health-sparrow/contact-us "Contact Us") ## Footer Column 3 - [Careers](https://careers.sparrow.org/) - [Sparrow & Community Health](https://www.uofmhealthsparrow.org/um-health-sparrow-community-health) - [Primary Care](https://www.uofmhealthsparrow.org/departments-conditions/all-departments/primary-care-practices) - [Emergency](https://www.uofmhealthsparrow.org/our-hospitals-services/emergency-rooms) - [Price Transparency](https://www.uofmhealthsparrow.org/patient-resources/financial-resources/standard-charges "Price Transparency and Standard Charges") ## Footer Column 4 - [Urgent Care](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now/university-michigan-sparrow-urgent-care) - [Walk-in Care](https://www.uofmhealthsparrow.org/our-hospitals-services/get-care-now/walk-care) - [Physician's Health Plan](https://www.uofmhealthplan.org/) - [For Healthcare Professionals](https://www.uofmhealthsparrow.org/healthcare-professionals) - [Event Calendar](https://www.uofmhealthsparrow.org/eventcalendar "UM Health-Sparrow Events") ## Footer Bottom - © 2026 University of Michigan Health-Sparrow. - All rights reserved. - [Legal & Policies](https://www.uofmhealthsparrow.org/legal-policies) - [Nondiscrimination, Accessibility & Language Services](https://www.uofmhealthsparrow.org/accessibility) - [Privacy Policy](https://www.uofmhealthsparrow.org/privacy-policy) - [Sitemap](https://www.uofmhealthsparrow.org/sitemap) - [Terms of Use](https://www.uofmhealthsparrow.org/home/terms-use) Unsupported Browser\!** This website will offer limited functionality in this browser. We only support the recent versions of major browsers like Chrome, Firefox, Safari, and Edge. ×
Readable Markdown	## Overview Shellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and mollusks. Examples are shrimp, crabs, lobster, squid, oysters, scallops and snails. Shellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening. If you think you have shellfish allergy, talk to your health care provider. Tests can help confirm the allergy so you can take steps to avoid future reactions. ## Symptoms Shellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include: - Hives - Itchy, irritated skin - Nasal stuffiness (congestion) - Swelling of the lips, face, tongue and throat, or other parts of the body - Wheezing or trouble breathing - Coughing and choking or a tight feeling in the throat - Belly (abdominal) pain, diarrhea, nausea or vomiting - Dizziness, lightheadedness or fainting ### Anaphylaxis Allergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to — and worsens quickly. An anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal. Anaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include: - A swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe - Coughing, choking or wheezing with trouble breathing - Shock, with a severe drop in your blood pressure and a rapid or weak pulse - Severe skin rash, hives, itching or swelling - Nausea, vomiting or diarrhea - Dizziness, lightheadedness or fainting ### When to see a doctor Seek emergency treatment if you develop signs or symptoms of anaphylaxis. See a health care provider or allergy specialist if you have food allergy symptoms shortly after eating. ## Causes All food allergies are caused by an immune system overreaction. Your immune system identifies a harmless substance as being harmful. This substance is called an allergen. In shellfish allergy, your immune system mistakenly identifies a certain protein in shellfish as harmful. Your immune system is how your body protects itself, so it produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the shellfish protein, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream. This causes a reaction that leads to the symptoms of an allergic reaction. ### Types of shellfish There are several types of shellfish, each containing different proteins: - Crustaceans include crabs, lobster, crayfish, shrimp and prawn - Mollusks include squid, octopus, mussels, snails, clams, oysters, abalone and scallops An allergy to crustaceans is the most common type. Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish. An allergy to fish — such as salmon, tuna or catfish — is a different seafood allergy from an allergy to shellfish. Some people who are allergic to shellfish may still be able to eat fish, or they could be allergic to both. Your health care provider can help you determine what is safe to eat. ## Risk factors You're at increased risk of developing shellfish allergy if allergies of any type are common in your family. Though people of any age can develop shellfish allergy, it's more common in adults. In fact, shellfish allergy is the most common food allergy in adults. Among adults, shellfish allergy is more common in women. Among children, shellfish allergy is more common in boys. ## Complications In severe cases, shellfish allergy can lead to anaphylaxis, a dangerous allergic reaction that can be life-threatening. When you have shellfish allergy, you may be at increased risk of anaphylaxis if you have: - Asthma - Allergic reactions to very small amounts of shellfish (extreme sensitivity) - History of food-induced anaphylaxis - Strong family history of allergy Anaphylaxis is treated with an emergency injection of epinephrine (adrenaline). If you are at risk of having a severe allergic reaction to shellfish, you always should carry injectable epinephrine (Auvi-Q, EpiPen, others). ## Prevention If you have shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people. ### Avoiding shellfish - Be cautious when dining out. When dining at restaurants, always check to make sure that the pan, oil or utensils used for shellfish aren't also used to prepare other foods, creating cross-contamination. It might be necessary to avoid eating at seafood restaurants, where there's a high risk of cross-contamination. - Read labels. Cross-contamination can occur in stores where other food is processed or displayed near shellfish and during manufacturing. Shellfish may be in fish stock or seafood flavoring. Read food labels carefully. Shellfish is not usually a hidden ingredient. Companies are required to label any product that contains crustacean shellfish or certain other foods that often cause allergic reactions. However, these regulations don't apply to mollusks. - Keep your distance. You may need to completely avoid places where shellfish are prepared or processed. Some people react after touching shellfish or inhaling steam from cooking shellfish. ### Be prepared If you have shellfish allergy, talk with your health care provider about carrying emergency epinephrine and how to use it. Consider wearing a medical alert bracelet or necklace that lets others know you have a food allergy. ### Iodine or radiocontrast dye One thing you don't need to worry about is if you'll also be allergic to iodine or radiocontrast material that's used in some imaging tests. Even though shellfish contain small amounts of iodine, shellfish allergy is unrelated to the reactions some people have to radiocontrast material or iodine. ## Diagnosis To find out if you have shellfish allergy, your health care provider will ask about your symptoms and do a physical exam to find or rule out other medical problems. A history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy. But the symptoms could also be caused by something else, such as food poisoning. Allergy testing is the only sure way to tell what's causing your symptoms, so your provider may recommend one or both of these tests: - Skin prick test. Small amounts of the proteins found in shellfish are pricked into skin on your arm or upper back. You're then watched for an allergic reaction. If you're allergic, you'll develop a raised bump (hive) at the test site on your skin. This typically takes about 15 to 20 minutes. Allergy specialists usually are best equipped to perform allergy skin tests. - Blood test. A blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies. Medically supervised food challenges can be performed if the diagnosis still isn't clear after allergy testing. ![Skin surface showing a positive reaction to allergy test](https://www.uofmhealthsparrow.org/sites/default/files/mayo-api/popup/d/DS00174_%20DS00339_%20DS00773_%20DS01067_%20MY00131_IM01607_aa7_dimethu_jpg.jpg) ## Treatment The only sure way to prevent an allergic reaction to shellfish is to avoid shellfish. But despite your best efforts, you may come into contact with shellfish. If you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection. Regularly check the expiration date on the packaging to make sure it's current. Carry injectable epinephrine (Auvi-Q, EpiPen, others) with you at all times. Epinephrine is typically given at the first sign of an allergic reaction. A second dose may be needed if symptoms recur. After you use epinephrine, seek emergency medical care, even if you start to feel better. ## Preparing for an appointment You're likely to start by seeing your family health care provider. Or you may be referred directly to an allergy specialist. ### What you can do Prepare for your appointment by making a list of: - Symptoms, including any that may seem unrelated to an allergy - Family history of allergies and asthma, including specific types of allergies if you know them - Medications, vitamins, herbs or other supplements you're taking, and the dosages - Questions to ask your health care provider Questions related to shellfish allergy include: - Are my symptoms most likely due to an allergy? - Will I need any allergy tests? - Should I see an allergist? - Do I need to carry epinephrine? - Are there brochures or other educational materials I can have? What websites do you recommend? Don't hesitate to ask other questions, as well. ### What to expect from your doctor Your health care provider may ask you questions, such as: - What symptoms are you having? How severe are they? - When did you notice your symptoms? - Have you reacted to shellfish in the past? - What kind of shellfish did you eat? - How soon after eating shellfish did your symptoms occur? - What other foods did you eat during your meal? Don't forget sauces, beverages and side dishes. - Did others who dined with you have similar symptoms? - Is there a history of allergy in your family? - Do you have other allergies, such as hay fever? - Do you have asthma or eczema (atopic dermatitis)? ### What you can do in the meantime Avoid eating or touching any type of shellfish while waiting for your appointment.
Shard	194 (laksa)
Root Hash	15754692202894961194
Unparsed URL	org,uofmhealthsparrow!www,/departments-conditions/conditions/shellfish-allergy s443