Exercise-induced Anaphylaxis as a Cause of Syncope

BackgroundExercise-induced anaphylaxis (EIA) is an under-recognized condition that is a distinct physical allergy. Triggers include varying amounts of exercise, alone or in combination with certain foods or medications (food-dependent EIA, or FDEIA). Therapy is identical to that of any immunoglobulin E-mediated allergic reaction.ObjectivesThis case is reported to increase awareness among emergency physicians of EIA and FDEIA.Case ReportA 57-year-old man was found with a diffuse erythematous rash after eating a wheat bagel and walking up five flights of stairs. Emergency medical services found him hypotensive and combative. In the Emergency Department, the patient’s blood pressure was 72/27 mm Hg, with an oxygen saturation of 97% on non-rebreather mask. The physical examination was notable for bilateral inspiratory crackles in the lower one-third of the lungs. He received intravenous (i.v.) diphenhydramine 25 mg, i.v. methylprednisolone 125 mg, and 1 L of normal saline, after which his blood pressure improved to 110/54 mm Hg. He was admitted to the hospital where his recovery was uneventful.ConclusionEIA and FDEIA are uncommon forms of physical allergy, but they represent important entities for emergency physicians to consider. Recognition of the association with exercise is key, as recurrences can be prevented by avoiding triggers.