Food-Dependent Exercise-Induced Anaphylaxis on a Nontraditional Timeline.

Food-dependent exercise-induced anaphylaxis (FDEIA) is a rare but potentially severe allergic reaction that can occur upon eating a specific food followed by exercise. It is triggered by the combination of a food allergen and exercise as a cofactor. We present one of the few documented FDEIA instances with a reversed sequence of ingestion after exercise. A 14-year-old male with no history of food allergy developed anaphylaxis after ingestion of a new protein drink, shortly after strenuous activity. His symptoms included facial angioedema, pruritus, and cough. He was taken to the emergency department and treated with epinephrine, diphenhydramine, and prednisone, with rapid improvement. At follow-up, serum tryptase, C4 and C3 complement, chronic urticaria index, and C074-IgE gelatin values were normal. Skin prick testing (SPT) demonstrated sensitization to trees, grasses, and weeds. Peas, bananas, and strawberries were potentially cross-reactive ingredients in the drink, and negative on SPT. Additionally, the patient had consumed these foods in the past without experiencing a similar reaction. The patient was informed of possible FDEIA and was prescribed an epinephrine auto-injector (EpiPen). He was counseled on avoiding strenuous exercise two hours before and after ingestion of foods that have cross-reactivity to environmental aeroallergens seen on his SPT. In most FDEIA cases, symptoms typically develop after physical activity when the patient has ingested a food to which they are sensitized. Given the possibility of presentation in a reversed sequence, providers should continue to consider FDEIA as a diagnosis when the ingestion event occurs after the exercise event.