A randomized double-blind comparison of PUVA-etretinate and PUVA-placebo in the treatment of chronic plaque psoriasis.

Twenty-eight patients with chronic plaque psoriasis affecting 20-40% of their body surface were treated with either PUVA and placebo (thirteen patients) or PUVA and etretinate (0.75 mg/kg) (fifteen patients). PUVA was given three times a week for a maximum of 10 weeks after a 2-week period on placebo or etretinate alone. Four patients failed to clear with PUVA and placebo compared with one patient with PUVA and etretinate, and the mean total UV-A dose to clear was lower with etretinate (mean = 62.1 J/cm2) than with placebo (mean = 77.3 J/cm2) but none of these differences were significant. Because the additional response to etretinate was only marginal, whilst unwanted effects were common, we found no advantage in adding etretinate to PUVA.