Scombroid Poisoning Masquerading as a Fish Allergy

Tuna and mackerel belong to the Scombridae family of fish. These fish naturally contain a high level of the chemical, Histidine. It turns out that a bacteria in inadequately refrigerated fish (not limited to this family of fish) is able to convert Histidine to Histamine, the chemical that all allergy sufferers want to avoid like the plague. Histamine is released in large quantities in people who have hay fever, allergic asthma, and allergic hives; it is, in large part, responsible for the allergic symptoms that occur with exposure to a specific trigger. Patients with scombroid poisoning develop allergy-like symptoms within an hour of eating "bad" fish: flushing, hives, gastrointestinal discomfort, and shortness of breath. There are tests available to distinguish "poisoning" from "allergy."  Immediate medical attention should be sought if these symptoms occur.

Take home message: Seared Ahi Tuna sandwiches do not have to be avoided for life if you have been "poisoned." Scombroid poisoning can masquerade as a fish allergy and fool people into a life-long avoidance of their favorite food.