Notices: 39th Annual Meeting of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition Dresden, Germany, June 7-10, 2006: Abstracts: PG3-19
To compare Atopy Patch Test (APT) and Skin Prick Test (SPT) to double blind placebo-controlled food challenges (DBPCFCs) for late-phase reactions to milk, egg and wheat in children with atopic dermatitis (AD).
All the 131 consecutive children [(80 M (61%); median age: 44 mo (range 4 to 151 mo)] with AD and suspected of late-phase food-related clinical symptoms were investigated with SPT, APT and DBPCFCs.
Overall, we performed 512 DBPCFCs (256 with food: 85 milk, 100 egg, 71 wheat) and 77 (15%; all with food) were positive [33 for cow's milk (38%; 17 late); 40 for egg (40%; 13 late) and 4 for wheat (6%; 3 late). APT resulted positive for milk in 23 children (18,6%), for egg in 42 (33,6%) and for wheat in 7 (5,5%) while SPT were positive for milk in 26 (19,8%), for egg in 68 (51,9%) and for wheat in 6 (4,6%). The SS, SP, PPV and NPV of SPT and APT in assessing a late phase reaction to food are shown in the table.
Logistic regression showed that SPT and APT were significantly associated with a late phase reactions to milk (OR = 3,7; 95%CI: 1-12 and OR = 4,4; 95%CI: 1-14 respectively) and both positive tests quadruplicates the risk of a positive challenge. However, only APT was predictive for late phase reactions to egg (OR = 11; 95%CI: 2-60) and wheat (OR = 5,4; 95%CI: 1-8).
Our findings confirm that the APT may be a valuable additional tool in the diagnostic work-up of food allergy in children with AD because of its high specificity and sensibility for late-phase clinical reactions especially for egg and wheat but it can not replace DBPCFC.
Conclusion: APT identify children not at risk for late phase reactions to food however DBPCFC must be still considered the diagnostic gold standard test.