Role of oral food challenges in the diagnostic work-up of food allergy in atopic eczema dermatitis syndrome.

The diagnosis of food allergy in infants and children is still a challenging task for the pediatrician. While immediate-type allergic reactions to foods can be diagnosed quite easily, late-phase reactions, e.g. in atopic dermatitis, often represent a diagnostic challenge. Once classical diagnostic procedures such as history, skin prick tests, atopy patch test, and specific immunoglobulin E in serum have been exhausted, double-blind, placebo-controlled food challenges represent the state of the art. After an oligo-allergenic diet, suspected foods or placebo are given in a titrated manner until a clear clinical reaction or the highest dose. The observation period should be 48 h in the case of atopic dermatitis. Constant clinical monitoring is mandatory. Dietetic recommendations are given for 12 months. The effort involved in such a procedure is justified because it can help to avoid clinically relevant food allergens in some cases and in others can prevent children from being exposed unnecessarily to diets that may be harmful to them.