Worldwide prevalence of allergies to wheat proteins is estimated as 0.5% to 9%. In the USA, prevalence is 0.4% for adults and 0.4-1% for children. Estimates for the European Union range from 0.3% to 3.4%. Allergic reactions to wheat proteins are both IgE- and non-IgE-mediated. Celiac disease (1-2% prevalence in the USA) is an example of a non-IgE-mediated pathology. Here, IGHE is linked to celiac disease.