The purpose of this comparative study was to record the prevalence and to estimate the incidence of self-reported hand dermatosis in a cohort of upper secondary school pupils on two different occasions, in 1995 and 1997. A previously validated questionnaire was used. Of the 1273 pupils invited to participate, 1136 (89.2%) responded to the questionnaire. The 1-year prevalence increased, although not significantly, from 9.6% in 1995 to 10.5% in 1997. For girls, the 1-year prevalence increased significantly, from 12.4% to 15.7%, while for boys the 1-year prevalence decreased, but not significantly, from 6.7% to 5.1%. The cumulative incidence was significantly higher (P < 0.001) among the girls (10.5%) than among the boys (2.8%). Multiple logistic regressions showed that the highest risk factors for 1-year prevalence in 1995 were having self-reported childhood eczema, and a family history of atopic eczema or asthma. In 1997, the highest risk factors were self-reported childhood eczema, female gender and a family history of atopic eczema. This study has identified the point at which the genders diverge with regard to hand dermatosis, with boys tending to recover, while girls show a steady or even increasing prevalence.