Food allergy and atopic dermatitis

Food allergy can be observed in a subgroup of atopic patients, such as patients suffering from atopic dermatitis (AD). Approximately 30 % of children with moderate or more severe forms of AD and sensitization to food allergens show associated clinical symptoms of hypersensitivity. Many patients with AD or parents of affected children suspect food as being relevant trigger factors for AD. Patients who actually benefit from elimination diets must be identified by means of validated diagnostic procedures. In turn malnutrition and associated limitations of quality of life should be avoided in those patients for whom food allergy could be excluded. As determination of specific IgE, results of skin prick tests and the patient history often do not correlate with eczematous reactions to food allergens, oral food challenges supervised by allergologists still represent the diagnostic gold standard for elucidating the clinical relevance of sensitization. As eczematous lesions often deteriorate after a period of 6-48 h after food challenge, examination of the skin should also be performed on the following day. Moreover, in patients with AD, the challenge with a food allergen should be performed in a repeated test over 2 days.