Wheat-Dependent Exercise-Induced Anaphylaxis

Abstract

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is presently gaining attention. Patients with WDEIA experience allergic symptoms when they exercise following wheat consumption. Some patients may be advised to restrict wheat consumption or exercise because of repeated allergic symptoms without adequate diagnosis or examination. Japanese guidelines recommend that WDEIA should be diagnosed using provocation tests with wheat and exercise. After wheat consumption, patients exercise using a treadmill or an ergometer during provocation tests. Once WDEIA is diagnosed, patients should not consume wheat before physical activity. Exercise is allowed at least 4 h after wheat intake. They may consume wheat if they do not exercise after wheat consumption, and they may exercise without consuming wheat before exercising. All WDEIA patients should be instructed regarding use of adrenaline auto-injector and should carry one with them. Some patients may respond to prophylactic treatment with anti-histamines. However, there is no established drug for preventing WDEIA; moreover, there is inadequate evidence for routine administration of these prophylactic drugs. Cofactors like nonsteroidal anti-inflammatory drugs (NSAIDs) may directly modulate immune reactions and could exacerbate the condition. Hence, patients should avoid these cofactors. The emergency treatment of WDEIA does not differ from that of immediate-type food allergy or anaphylaxis. Exercise should be stopped when patients show food allergy symptoms. When patients show anaphylactic reactions, adrenaline should be quickly administered. Indications for adrenaline auto-injector use are severe symptoms like persistent coughing, breathing with wheeze, persistent abdominal pain, and confusion. However, there is no evidence that anti-histamines and corticosteroids have lifesaving effects. Consequently, it is important that adrenaline auto-injector is used in an appropriate setting and that the patient is transferred to a hospital immediately. The mechanisms of WDEIA development are unknown. Further research is needed to clarify the mechanisms involved so that it can be treated.