Allergy to crustacea is quite common. People who are sensitive can react to different types of crustacean,– shrimps, prawns and lobsters.
Crustacea often cause severe reactions, and some people can react to cooking vapours.
Some people allergic to crustacean also react to molluscs.
Molluscs include squid, octopus, (cephalopods) Gastropods – whelks, snails, Bivalves – shellfish,clams, oysters, scallops, mussels
Molluscs and crustaceans are allergenically distinct from fin fish.
Products which may contain molluscs and crustacea include:
Sauces (eg fish sauce)
Seafood flavouring (eg clam)
it is possible for an allergic reaction to occur from cooking odours or handling of shellfish.
Thanks to Food Standards Australia for this information.