Anisakis simplex-induced anaphylaxis.

In recent years, Anisakis simplex has been shown to be an important etiologic agent responsible for food allergy and for gastrointestinal anisakiasis. We report a 61-year-old woman presenting with generalized urticaria and subsequent anaphylaxis after ingestion of raw mackerel. She rapidly recovered with administration of epinephrine and endoscopic extraction of an A. simplex larva. Serologic testing revealed specific IgE antibody to A. simplex was positive whereas that to mackerel was negative. She was diagnosed as IgE-mediated hypersensitivity to A. simplex. Patients diagnosed as fish-related or idiopathic allergy should be examined for evidence of Anisakis-induced allergy.