A Multicenter Evaluation of Diagnosis and Management of Omega-5 Gliadin Allergy (Also Known as Wheat-Dependent Exercise-Induced Anaphylaxis) in 132 Adults

BACKGROUND: Omega-5 gliadin allergy (also known as wheat-dependent exercise-induced anaphylaxis) is a rare allergy to wheat that often presents with intermittent severe anaphylaxis in the context of a cofactor, such as exercise. OBJECTIVE: To undertake a detailed clinical characterization of the largest cohort of patients with omega-5 gliadin allergy to date. METHODS: We retrospectively analyzed the demographic characteristics, presentation, investigation, and management of 132 patients presenting with omega-5 gliadin allergy in 4 UK centers. RESULTS: There were significant delays in diagnosis of 1 to 5 years (40% of patients) and more than 5 years (29% of patients). The commonest cofactors were exercise (80%), alcohol (25%), and nonsteroidal anti-inflammatory drugs (9%). A minority of patients (11%) had no identifiable cofactor. The level of specific IgE to omega-5 gliadin does not predict the severity of allergic reactions. Patients who adhered to a gluten-free diet and those who avoided wheat in combination with exercise achieved the largest reductions in subsequent allergic reactions of 67% and 69%, respectively. CONCLUSION: Omega-5 gliadin allergy is a rare wheat allergy that presents with severe anaphylaxis. The diagnosis is frequently delayed, and therefore we recommend that all adult patients presenting with anaphylaxis of unclear cause should have omega-5 gliadin specific IgE tested. A gluten-free diet or avoidance of wheat-based meals in combination with exercise (if the cofactor is exercise) helps to significantly decrease the risk of future allergic reactions. However, antihistamines and an epinephrine autoinjector must always be prescribed because one-third of patients continue to have allergic reactions despite dietary advice. (C) 2018 American Academy of Allergy, Asthma & Immunology