Food allergy and asthma.

Food allergy (FA) is one of the causes of atopic dermatitis (AD), of acute urticaria, of reactions of the gastrointestinal tract, and of acute systemic anaphylaxis, but its role in asthma appears to be less clear. The prevalence and incidence of subjects with food-induced wheezing have not been well studied. In addition, the number of subjects with proven food-induced wheezing by double-blind, placebo-controlled oral food challenge (DBPCOFC) has been small. At the moment wheezing is considered unusual in food-hypersensitive subjects, and wheezing as the unique symptom of FA is rare. Furthermore, most cases of food-induced asthma have been observed in children. Food allergy may trigger allergic respiratory symptoms through two main routes: ingestion or inhalation. Children with asthma, who are allergic to foods, present some particular features such as AD and a related significantly elevated total serum IgE level. Alternatively, FA may occur in patients who are "high IgE responder" and more prone to become sensitive to many allergens, including foods. Therefore, children with asthma and a history of AD and/or elevated total serum IgE level should be carefully assessed for FA. We have shown that a significant proportion of children with IgE-mediated cow's milk allergy experienced asthma following DBPCOFC with cow's milk.