Contact allergy in relation to hand eczema and atopic diseases in north Norwegian schoolchildren.

Patch testing was carried out in 424 schoolchildren (223M, 201F), aged 7-12 years, in northern Norway. In 99 (23.3%) of these children, one or more allergic patch test reactions were demonstrated; 30 children reacted to two and 6 to three or more substances; 53 irritant reactions were recorded in 33 (7.8%) of those tested. From a total of 144 positive tests, the most common allergen was nickel (14.9%), followed by cobalt (5.7%), kathon CG (5.2%), lanolin (1.7%) and neomycin (1.4%). Both allergic and irritant reactions were found twice as frequently in girls as in boys. Positive patch tests were significantly more frequent in atopic (28.8%) than in non-atopic (17.9%) children, being most pronounced in atopic girls (37.4%). Hand eczema was reported to have occurred or to be present in 6.5% of cases. Twenty-nine of 36 children reporting hand eczema participated in the clinical examination. Altogether 15 (3.5%) children had hand eczema at the time of the clinical examination but 12 of these children had no previous history of hand eczema. In 14 of these 15 subjects, the eczema was localized to the back of the hands, with 13 having atopic dermatitis. In 4 of these 15 children, an allergic patch test reaction was found; however, in only 2 of these 4 was the test considered to be clinically relevant for the diagnosis allergic hand eczema. In conclusion, irritant hand eczema may occur in early childhood and is most prevalent in children with atopic dermatitis.