Crab allergy

Source

Information provided in co-operation with the Informall project.

There are many species of edible crabs. Crabs are eaten cooked crab but also cooked in mixed seafood dishes such as Spanish paella. Crabsticks and surimi contain both finfish meat and some crab for flavour.

Crab allergy

Crabs along with crayfish, lobsters and shrimps are crustaceans. Food allergy to crustaceans is relatively common, symptoms ranging from mild oral allergy to severe symptoms such as anaphylaxis. Cooking does not remove the allergen. Crustacea are the third most important cause of food induced anaphylaxis after peanuts and tree nuts (cashews, almonds, pecans, walnuts, etc.). Thus crustacea and products thereof are listed in annex IIIa of the EU directive on labelling of foods and must be labelled when used as ingredients in pre-packaged food.

Most allergy to crustacea seems to involve a muscles protein called tropomyosin, which is very similar in a wide range of crustacean foods. As a result someone with allergy to tropomyosin from one kind of crustacean is likely to react to others. Thus individuals with allergy to one kind of crustacean are usually advised to avoid all types of crustacean foods.

In addition, some individuals with allergies to insects such as cockroach or moths can suffer food allergy to crustacean foods. Whilst most individuals with allergy to shrimps (crustacea) can tolerate molluscs, individuals with allergy to both types of shellfish have been reported. However, individuals allergic to finfish (such as cod or salmon) do not generally have allergies to shellfish.

The main allergenic proteins in crabs are tropomyosin and Cha f1.

More information

• Overview of clinical studies
• Biochemical data on Tropomyosin
• Biochemical data on Cha f1