Fish and shellfishf24

Shellfish allergy

Shrimp is used to test for shellfish allergy, which often causes severe reactions and is usually lifelong. People who react to shrimp and prawns often also react to crab, lobster and crayfish.

Allergen
Shrimp
Allergen code
f24
Key allergens
Tropomyosin
Included in
2 tests
Contents
  1. What is shellfish allergy?
  2. Symptoms
  3. Where shellfish is found
  4. Cross-reactivity
  5. How to get tested
  6. Frequently asked questions

What is shellfish allergy?

Shellfish allergy means that the immune system reacts to proteins in crustaceans such as shrimp, prawns, crab, lobster and crayfish, and sometimes in molluscs such as mussels and squid. The most important allergen is tropomyosin, a muscle protein that withstands heat. The allergy often starts in adulthood and is usually lifelong.

Symptoms

  • Itching and swelling in the mouth and throat
  • Hives
  • Vomiting, stomach ache and diarrhoea
  • Breathing difficulties
  • A severe allergic reaction (anaphylaxis)

Reactions can also be triggered by the steam when shellfish is being boiled.

Where shellfish is found

Shrimp and other shellfish are found in prawn sandwiches, shrimp salads, paella, sushi, Asian dishes and soups, and shrimp paste is used as a flavouring in many Asian cuisines. Crustaceans and molluscs are among the allergens that must always be declared on the ingredients list.

Cross-reactivity

Tropomyosin is similar across different crustaceans, so people who react to shrimp often also react to crab, lobster and crayfish. Similar tropomyosin is found in mites and cockroaches, which is why some people with house dust mite allergy can also react to shellfish. If you want to know whether you react specifically to tropomyosin, you can test for Pen a 1.

How to get tested

Shrimp (allergen code f24) is included in our Shellfish allergy test, which also measures tropomyosin Pen a 1, and in our Fish and shellfish allergy test. The test shows whether you have IgE antibodies to shrimp.

Frequently asked questions

Is shellfish allergy an iodine allergy?

No. Shellfish allergy is caused by proteins in shellfish and has nothing to do with iodine. Nor does it mean any increased risk with X-ray examinations that use iodine contrast.

Can I eat fish if I am allergic to shellfish?

Fish and shellfish have different allergens, so most people with shellfish allergy tolerate fish. Still, be careful with dishes where fish and shellfish are cooked together.

Often cross-reacts with

This text is general information and does not replace an assessment by a healthcare professional. In an emergency, call 112. If you have questions about your health, contact your doctor.

Tests for shellfish allergy

You take the sample yourself at home. The tests measure IgE antibodies in a capillary blood sample.

Fish and shellfish

Fish and shellfish allergies often last a lifetime. People who react to one type of fish often react to several, because the most important proteins are similar.

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Find the right test in 1 minute

We offer three types of tests - choose the one that suits you best.

Self-test: quick response at home directly.
Lab test - sampling at home: Take the sample yourself and send it to a lab for analysis.
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You will receive clear information about what the test shows, how it is used and what the next steps may be.

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