Objective: To evaluate the effect of a secondary prevention programme with education on skin care and individual counselling versus treatment as usual in healthcare workers with hand eczema. Design: Randomised, observer blinded parallel group superiority clinical trial. Setting: Three hospitals in Denmark. Participants: 255 healthcare workers with self reported hand eczema within the past year randomised centrally and stratified by profession, severity of eczema, and hospital. 123 were allocated to the intervention group and 132 to the control group. Interventions: Education in skin care and individual counselling based on patch and prick testing and assessment of work and domestic related exposures. The control was treatment as usual. Main outcome measures: The primary outcome was clinical severity of disease at five month follow-up measured by scores on the hand eczema severity index. The secondary outcomes were scores on the dermatology life quality index, self evaluated severity of hand eczema, skin protective behaviours, and knowledge of hand eczema from onset to follow-up. Results: Follow-up data were available for 247 of 255 participants (97%). At follow-up, the mean score on the hand eczema severity index was significantly lower (improved) in the intervention group than control group: difference of means, unadjusted -3.56 (95% confidence interval -4.92 to -2.14); adjusted -3.47 (-4.80 to -2.14), both P