Methods: Patients underwent a complete history, physical exam, and skin prick testing by classical method.
Results:
Case 1: A 23 year old Asian Male presented with anaphylaxis following cashew ingestion and post prandial exercise. This was the first episode of anaphylaxis despite previous exposure to cashews and exercise independently. Patient ingested cashews and went for a jog 30 minutes later. His symptoms of anaphylaxis included urticaria and ocular swelling. Skin prick testing generated positive results to cashew, with measurements of 10mm/30mm (wheal/flare). Controls of histamine and saline measured were 10mm/30mm and 0mm/0mm, respectively.
Case 2: A 42 year old Caucasian Male presented with anaphylaxis following shrimp ingestion and post prandial exertion. This was the first episode of anaphylaxis despite previous exposure to shrimp and exercise independently. Patient ingested shrimp and went for a brisk walk 30 minutes later. His symptoms of anaphylaxis included full body urticaria and shortness of breath. Skin prick testing generated negative results to shrimp and shellfish mix, with measurements of 0mm/0mm and 0mm/0mm (wheal/flare). Controls of histamine and saline measured were 10mm/30mm and 0mm/0mm, respectively.
Conclusions: The previous cases describe anaphylactic reactions after food ingestion followed by post prandial exercise. The precise pathophysiology of this rare syndrome is poorly understood, however it is believed that allergen absorption is increased in a post-exercise state. The contrast in our patients’ results of their skin prick tests demonstrate that patients may or may not have food-specific IgE but still can experience food dependent exercise induced anaphylaxis. Mainstay treatment for food dependent exercise induced anaphylaxis is recommending exercising only on an empty stomach. The consideration of food dependent exercise induced anaphylaxis in cases of unexplained anaphylaxis is important as reactions can be life threatening and clinicians should be reminded of the importance of thorough history taking.