Crustaceans are a group of invertebrates which include lobster, prawn, scampi, crab and shrimp. Note in Europe that crustaceans and molluscs are considered to be 2 separate food groups whose allergens need to be declared in packaged food. In the US these are both grouped under the term 'shellfish'.
The WHO allergen index covers 21 species of crustaceans linked to allergic reactions and 7 main groups of allergens.
15 species of invertebrates have been found to contain the allergen Tropomyosin, which is a protein found in exoskeletons.
Arginine Kinase allergens have been found in 6 species, mostly in shrimp.
Myosin allergens have been found in 6 species, mostly shrimp and crab. Myosin is a protein found in animals involved in movement and muscle contraction.
Sarcoplasmic calcium binding protein allergens have been found in 5 species of shrimp and crab. These are proteins found in the muscle of crustaceans.
These identified allergens are related to food allergy - there are an additional 146 allergens identified in this group which link to airborne and airway allergens, which means just cooking crustaceans can be a problem for sufferers of this allergy.
Crustacean Allergy has not been linked to any syndromes.
Crustacean allergy is linked to shellfish allergy; oysters, abalone, squid and snail all contain the main allergen - tropomyosin.
Catfish, some types of salmon and tilapia are types of fish which have also been identified as containing the allergen tropomyosin, there may be cross reactivity between eating certain types of fish and crustaceans.
There is a lot of research into a link between dust mite allergy and crustacean allergy, this is again attributed to the common allergen - tropomyosin.