A case of hen's egg-dependent exercise-induced immediate-type allergy

Dear Editor, Hen's egg is a major food allergen among children in Japan, and the main source of allergens is the egg white rather than the yolk. The major allergens in egg white are ovomucoid, ovalbumin, conalbumin, and lysozyme. The antigenicity of ovomucoid does not change when exposed to heat or digestive enzymes. Chicken serum albumin (Gal d 5) has been reported to be an allergen in the yolk. Generally, patients with hen's egg allergy naturally acquire tolerance with age. We report a case of food-dependent exercise-induced immediate-type allergy caused by ingestion of hen's egg. A 16-year-old girl with a history of hay fever experienced episodic eyelid swelling on three occasions. Each episode occurred during her commute to school by bicycle, after eating breakfast that included hen's egg. No other symptoms besides eyelid swelling had developed in any of the three episodes.