Wheat allergy – clinical implications and management

Abstract

Grain allergies are common food allergies, that are typically but not only seen in individuals with other associated food allergies. The immunologic responses to grain proteins can be IgE and/or non-IgE mediated. Wheat allergy is the most common of the cereal grain allergies. It usually begins in early childhood and is outgrown by adolescence, although some retain it beyond the teenage years. Immunoglobulin E (IgE)-mediated wheat allergy is reported to affect 0.2 to 1.3 percent of children in Europe and 0.4 percent of children in the United States. The onset of wheat allergy in adulthood is typically not seen, unless it is related to an occupational exposure. Epidemiologic data for the other grains is largely missing. Immunoglobulin E (IgE)-mediated food-triggered reactions generally occur immediately, within minutes to two hours after ingestion. These reactions can present with skin, oropharyngeal, upper and lower respiratory tract, gastrointestinal tract, and/or cardiovascular signs and symptoms. The reactions can vary from mild cutaneous reactions to life-threatening anaphylaxis. Positive diagnose is based on determining the plasmatic level of specific IgE and performing skin prick test for wheat, methods that have poor specificity and sensitivity in predicting oral food challenge test outcomes. The gold standard test remains oral food challenge (OFC) test for wheat. Most of the studies have proven its utility, even in children with high levels of wheat specific IgE. The diagnose of non-IgE mediated reactions is based on clinical presentation and plasmatic levels of specific antibodies, other than IgE. The management of grain allergy does not differ from that of other food allergies. It requires instructions on avoidance and treatment of reactions in the event of accidental exposure. It includes education about grain alternatives. It also includes monitoring for nutritional issues and for the resolution of the allergy. Preliminary data on specific oral tolerance induction to wheat through oral desensitization protocols have shown some promise in children, but it is still considered an experimental therapy.