Resolution of fish allergy: a case report

Background: Fish allergy is one of the most common food allergies, and it is believed to be lifelong. There are no published reports, to my knowledge, of resolution of fish allergy. Objective: To report a case of resolution of IgE-mediated fish allergy. Methods: The patient was a 68-year-old man with a history of fish-induced anaphylaxis who had previously undergone prick-puncture skin testing to several fish species. Additional skin testing was performed in October 2002. Subsequently, he underwent an open challenge with halibut. Results: The patient's previous skin tests showed him to have strongly positive reactions to several fish species. However, testing performed in October 2002 produced negative results to a number of fish species. In addition, he tolerated an open challenge with halibut. In the ensuing 8 months, he has regularly ingested salmon, cod, and halibut without experiencing any allergic reactions. Conclusions: This case illustrates that fish allergy is not invariably lifelong. Hence, allergists should consider reevaluating the allergy status of adults with a history of fish hypersensitivity.