[Feature of food allergy developed during infancy (1)--relationship between infantile atopic dermatitis and food allergy].

Background Most of food allergy (FA) cases during childhood start as infantile atopic dermatitis (AD) at the ages of a few months old. We tried to clarify the association between infantile AD and FA during infancy. Methods We analyzed relationship between AD and FA during infancy among patients with 208 cases, who had visited our outpatient clinic with chief complaint of eczema from 1998 to 2000. Results Among 208 cases, 148 cases (71%) were diagnosed as infantile AD, moreover 109 cases (74%) were diagnosed as FA among infantile AD. The most frequent food antigens among infantile AD were egg (72.3%), cow's milk (39.9%), wheat (12.2%) and soybean (7.4%), respectively, in addition to these food antigens, food allergy was widely recognized against peanuts, sesame, meats, buckwheat, fishes and potato. In terms of food antigen, 44 cases with single food allergy against egg were seen out of 46 single allergy cases, whereas 36 cases with double food allergy against both egg and cow's milk were seen in 63 multiple food allergy cases. Although the value of antigen specific IgE against egg and cow's milk was recognized for the diagnosis of food allergy during infancy, even cases with negative IgE against those foods were proved to be food allergy by food elimination and provocation tests. In contrast to egg and cow's milk, positive IgE against rice, soybean, and wheat did not always correlate with the results of the diagnosis of food allergy. Concerning risk factors of AD, family history of any allergy diseases and passive smoking were recognized in comparison with infantile eczema. Neither the nutrition method nor incomplete elimination of diet during pregnancy and lactation had anything to do with the development of AD. Conclusion When infantile AD cases were not improved by environmental control, skin care and application of steroid ointment, it would be important for doctors to think of the possibility of FA.