Topical PUVA was compared with UVA for the treatment of chronic vesicular hand eczema in a double-blind randomized within-patient trial. Twelve of 15 patients completed 8 weeks' treatment and were followed up for 8 weeks. Both sides improved over the 8-week treatment period (p less than 0.05) and both remained substantially better objectively and subjectively at 8 weeks' follow-up. There was no statistical difference between assessments of the treated hands at any stage. Nine of the patients who completed the study answered a questionnaire up to 18 months later. In 4, eczema was healed, 3 were better on the PUVA-treated hand and 1 on the UVA-treated hand. It is possible that UVA alone is beneficial for chronic hand eczema.