Seafood Allergies Aren't What You Think

Patient Expert

I have allergies to salmon, but as a child I ate other kinds of fish like flounder and cod without allergic reactions. As an adult I avoid all kinds of fish. But according to a study presented by Dr. Sami Bahna of Lousiana State University at the American Academy of Allergy Asthma & Immunology (AAAAI) conference, my total avoidance of all fish may not be necessary.

He said in a presentation that fish allergy is not universal. In one study, 40% of fish allergic children tolerated fish other than the ones they're allergic to. Interesting right?

According to further studies, a fish allergy may occur in reaction to a certain part of a fish but not another. For example, dark muscle was proven to be less allergenic than white muscle; some people react to the roe of the fish but not the fish flesh; and some react to the shell of shellfish but not to the meat of shellfish. Fascinating I have a friend who's told me that her mother is allergic to the skin of the mango but not to the flesh. This is similar.

And there other ways that handling or ingesting fish can cause allergic reactions. The way fish is processed can affect its allergic properties: cooked versus raw fish for example. Boiling changes the protein profile of a fish and actually increases it allergenicity. However, treating shrimp with ultrasound decreases allergenicity in vitro (more studies are needed and more questions for consumers who may want to eat fish and seafood treated this way).

Dr. Bahna asserted that many times fish allergy reactions might, be in fact, a reaction to something else other than the actual fish. There are seafood associated toxins and parasites in many fish species and little is known about many fish toxins such as: vibro toxins, neurotoxins, saxitoxins and scombrotoxins. Fish can contain additives like chemical preservatives, coloring, spices and taste enhancers. Fish can also be contaminated by latex, other allergenic foods, botulism or toxic chemicals.

Will I be ordering the jumbo shrimp any time soon? Probably not. But, slowly and with an allergy action plan, I may try to reintroduce the fish that I could tolerate in childhood.