Allergenic Foods and their Allergens, with links to Informall

Crustacean Shellfish

Crustacean Shellfish at a market.
Crustacean Shellfish at a market


The group of crustacean shellfish comprises a range of members of which shrimps, prawns, crabs and lobsters are most relevant to human diet. They contribute considerably to human nutrition and the world economy32.

Allergy to crustacean shellfish seems to predominantly affect older children and adults, especially in regions with a high rate of consumption33. Crustacean shellfish allergic individuals regularly react to various different types of crustacean shellfish but can also react to molluscan shellfish and edible land snails, caused by the major shellfish allergen tropomyosin. The widespread occurrence of tropomyosin in other invertebrate species can cause crustacean allergic individuals to also react to non-dietary invertebrates (e.g. house dust mite, cockroach).

Symptoms of crustacean shellfish allergy range from mild local reactions in the oral cavity (oral allergy syndrome) to severe life threatening systemic reactions. Occasionally gastrointestinal and respiratory symptoms occur. Occupational exposure to crustacean shellfish aerosols during processing and food preparation can be associated with rhinitis and conjunctivitis34.

Since shellfish retains its allergenic potential even after heating, avoidance of all forms of shellfish is essential. Crustacean shellfish may be present in some processed instant foods (e.g. pizza, garnishes, sauces, salad dressings).

Crustacean shellfish is included in the Big-8 and the Codex Alimentarius allergen labeling recommendations for labeling of pre-packaged foods.

For more detailed information on these foods please follow the links:










Updated 10 March, 2014