THE EPIDEMIOLOGY OF FOOD ATOPY PATCH TESTS: A STUDY OF 335 UNSELECTED SCHOOL CHILDREN AGED 10 FROM TWO EUROPEAN COUNTRIES.

Objective: Atopy patch test (APT) is a consensus procedure for diagnosing food allergy, especially in children with atopic dermatitis. The prevalence of positive APT reactions which can be expected to be found in unselected populations of adults or children is largely unknown. Nor is it clear whether positive APT reactions are more frequent in atopic patients and whether APT results are influenced by factors such as sex, geographical settings and life-style. Study Design and Setting: In an unselected population of 335 schoolchildren aged 10 years from two European countries with some differences life style (Italy and Slovakia) we investigated the prevalence of positive ATP reactions after cow milk, hen egg, tomato and wheat flour. We also assessed a possible link between positive APT results and other laboratory characteristics of atopy (allergen skin prick tests, histamine skin reactivity and eosinophil cell counts). Results: Atopy patch tests for foods were each positive in 5-15 % of the tested subjects with about 21% having at least one positive APT result: in general, they were more frequently positive in Italian children. In both countries the prevalence of positive APT reactions was significantly higher in males than in females. No relationship was found between positive ATP results and histamine skin reactivity, skin prick tests for the tested food allergens or for inhalant allergens and eosinophil cell counts. Conclusion: The findings from this study in unselected children suggest that APTs frequently elicit positive responses in unselected children populations, especially in boys, with different frequencies for particular food allergen in different geographical settings independently from the presence of positive SPT reactions. [ABSTRACT FROM AUTHOR]