Foods and respiratory allergy.

Foods may induce respiratory symptoms by both reaginic and nonreaginic mechanisms. Asthma is one of the most common respiratory manifestations in children, and it is well known that many factors may provoke an attack. When considering the relationship between foods and asthma, we must keep in mind that food allergy may coexist with an inhalant allergy and that other nonallergens, such as pollutants, smoke, or additives, may modulate or modify bronchial reactivity and thus favor the food allergen action. In a study using clinical history, prick test, radioallergosorbent test, and double-blind food challenge, we demonstrated respiratory symptoms related to food allergy in 13 of 140 (9.2%) children with asthma. Asthma, in particular, was demonstrated in 8 of 140 (5.7%) patients. Food allergy respiratory symptoms are, in our experience, almost always associated with other clinical manifestations (e.g., cutaneous, gastrointestinal). The recognition of food-dependent IgE-mediated respiratory symptoms is essentially limited to those cases characterized by food allergy with asthmatic expression. It is possible, however, that in many cases foods may have a nonspecific role in the determination of asthma or in the preparation of bronchi for the possible consequent stimulus.