Combination of psoralens and ultraviolet A and ultraviolet B in the treatment of psoriasis vulgaris: a bilateral comparison study.

Forty-two adults with psoriasis vulgaris were treated total body thrice weekly with both ultraviolet B (UVB) and psoralens and ultraviolet A (PUVA) with the use of protocols shown to be effective with either treatment alone. Patients previously difficult to manage with either UVB or PUVA and at least 25% psoriasis were selected. No other treatment was used for 2 months prior to initiation or during the study. All patients tolerated treatments well and cleared in an average of only 11.3 treatments, less than half the number of treatments usually required with either PUVA or UVB. The mean UVB dose at clearing and the mean cumulative PUVA dose were less than half that normally required with either therapy alone. The total cumulative UVB dose was only 18% of that normally required with UVB. Bilateral comparison studies comparing the PUVA-UVB combination with PUVA and UVB found that whenever there was a clear difference it was always the combination that cleared more rapidly. The marked reduction of total cumulative energy required more rapidly. The marked reduction of total cumulative energy required may be a significantly smaller insult to skin and the marked reduction in joules/cm2 of UVB and joules/cm2 of PUVA at clearing may make it possible to provide effective maintenance therapy with either treatment at a markedly lower treatment dose. Hopefully, long-term side effects may thereby be markedly diminished.