Procedures in suspected food allergy in atopic dermatitis

The following position paper of the "Arbeitsgruppe Nahrungsmittelallergie der DGAI" (Task Force an Food Allergy of the German Society of Allergology and Clinical Immunology) summarizes different procedures, when food allergy is suspected in atopic dermatitis (neurodermatitis, atopic eczema). The problem is clinically relevant because many patients assume allergic reactions against foods being responsible for triggering eczematous reactions or worsening eczema. It is important to identify such patients who indeed benefit from an elimination diet and to avoid unneccessary diets. Elimination diets (especially in early childhood) are associated with the risk of malnutrition and additional emotional stress for the patients. The gold standard for the diagnosis of food-dependent reactions is to perforin placebo-controlled, double-blind oral food challenges because specific IgE, prick tests and anamnestic data often do not correlate with clinical reactivity. This is particularly true in the case of delayed eczematous skin reactions. The instrument of diagnostic elimination diets should be used before an oral provocation test. If multiple sensitisations against foods are discovered in a patient, an oligo-allergenic diet and a subsequent stepwise supplementation of the nutrition should be performed. If a specific food is suspected of triggering food allergy, oral provocation should be performed alter a diagnostic elimination diet. As eczematous skin reactions may develop slowly (i.e. within one or two days), we recommend that a repetitive test should be performed if the patient has not reacted to a given food an the first day of oral provocation. The position paper discusses various clinical situations for patients with atopic dermatitis, allowing for differentiated diagnostic procedures.