Late Breaking Poster Sessions

Abstract

Background: Atopic dermatitis (AD) and food allergy frequently co-exist in children. Both immediate and late reactions have been reported after oral food challenge. The aim of this study was to investigate the reactions occurring in children with AD during double blind, placebo-controlled food challenges (DBPCFC). Also, the frequency of positive DBPCFCs in children reporting exacerbations of eczema as their only symptom to foods was studied. Method: Between 2001 and 2011, children underwent DBPCFCs for one or more suspected food allergies as part of regular care. The history relating to the suspected food was obtained. Children and/or parents were questioned about current AD. Immediate symptoms were defined as symptoms occurring during the challenge, or within 2 h after the last dose. Symptoms were considered 'intermediate' when they occurred between 2 and 6 h and 'late' between 6 and 48 h after the last challenge dose. McNemar's test was used to test for statistical differences between frequencies on verum and placebo days. Results: Of the 682 children undergoing DBPCFC, 381 children (55.9%) had a current history of AD, of which 317 had a history of reactions to foods and 64 had no known ingestion of the food previously. Immediate reactions consisting of exacerbations of AD only occurred rarely [two patients out of 326 (0.6%) on verum days vs one patient on a placebo day (0.3%), not significant (n.s.)]. Comparing verum to placebo days, immediate symptoms other than AD were seen more frequently (39.6% vs 8.0% respectively, P <0.01), as was the combination of AD with other symptoms (4.3% vs 0% respectively, P <0.01). Intermediate reactions of exacerbations of AD, were seen rarely either on verum or placebo days (4.0% vs 3.1% respectively, n.s.). Late eczematous reactions were also rarely seen on either verum or placebo days (1.5% vs 1.2% respectively, n.s.). Of all 317 children with a history relating to the suspected food, 19 children had a history of only an exacerbation of AD. In these children 4 verum reactions and 8 placebo reactions occurred. Conclusion: In our population of children with AD and a history suggestive of food allergy, isolated eczematous reactions were seen rarely at any time point. When AD exacerbations occurred, they almost always occurred in combination with other symptoms. Our results thus suggest that children with an exacerbation of AD in the absence of other symptoms in their history are unlikely to be food allergic.