Food allergic reactions are now the leading cause of anaphylactic reactions treated in emergency departments in the US. It is estimated that there are 29,000 anaphylactic reactions to foods treated in emergency departments and nearly 200 deaths due to food allergies each year.
Seafood allergies – including scaly fish and shellfish (i.e. crustaceans and molluscs) – are the most common causes of food allergy. Seafood can be a powerful allergen for certain people, causing life-threatening reactions. Seafood allergies are life-long.
Shellfish Allergy – One type of shellfish, “Molluscs,” include Abalone, oysters, mussels, and squid (Calamari). Another type of shellfish, “Crustaceans,” include lobsters, "crayfish", prawns, crabs and shrimp.
Fish Allergy – Other types of seafood allergies include reactions to more common edible “scaly” and “bony” fish, such as cod, haddock, herring, sprat, halibut, mackerel, trout and salmon. Often patients are only allergic to certain species but are able to eat other seafood species without problems.
A patient reacting to seafood can sometimes be difficult if the adverse reaction was caused by a non-allergic reaction like food poisoning and/or a bacterial or viral infection, for example. The most commonly reported symptoms seen with this kind of allergy include: atopic dermatitis (eczema), urticaria (hives), asthma, anaphylactic shock and digestive symptoms.
As with most allergies, avoidance is key. Make sure to read all labels for foods, medicines, cosmetics, creams and ointments that may contain any type or amount of fish or shellfish. A history of allergic reactions shortly after exposure to fish or shellfish might suggest an allergy. However, this should be confirmed with a skin prick test or RAST. Talk to your doctor about a complete diagnosis.
SOURCE: This information should not substitute for seeking responsible, professional medical care. First created 1995; fully updated 1998; most recently updated 2005.
© Asthma and Allergy Foundation of America (AAFA) Editorial Board