Delayed food-dependent, exercise-induced anaphylaxis

Food-dependent, exercise-induced anaphylaxis (FDEIA) is a clinically distinct form of anaphylaxis in which symptoms occur only when the patient exercises within a few hours of eating the food. Its precise mechanism remains unclear and has been reported to have a wide spectrum of presentations. The objective of this report is to show that the onset of FDEIA can be delayed for several hours and to emphasize the critical need for having self-injectable epinephrine available at all times. Our patient had several episodes of FDEIA to wheat shortly after exercise since the age of 11 years. At 16 years of age, 5 hours after exercise that followed eating a wheat-containing meal, the patient developed severe anaphylaxis with loss of consciousness. Skin-prick test was positive (4+) to wheat but negative to 41 other foods. Serum tryptase level 2 hours after onset of anaphylaxis was elevated. Other laboratory findings were within normal ranges. This case indicates that FDEIA can have a delayed onset for several hours. Because such delayed onset is unpredictable and can be life-threatening, it might be prudent for such patients to avoid the offending food totally or to avoid exercising for at least 6 hours after eating the food and to keep self-injectable epinephrine easily available at all times.