A comparative study of different treatment frequencies of psoralen and ultraviolet A in psoriatic patients with darker skin types (randomized-controlled study)

Background: Photochemotherapy psoralen and ultraviolet A (PUVA) is a viable option for treatment of psoriasis. However, concerns about its side effects have raised the need to change current PUVA protocols. The aim of this study is to determine whether reducing the treatment frequency of PUVA to twice/week instead of three times/week would affect the efficacy of PUVA therapy. Patients and methods: The study included 20 psoriatic patients, randomized into two groups, 10 patients in each group. The first group received two weekly sessions, the second group received three. The study lasted until complete clearance or for 12 weeks (endpoint). Psoriasis area and severity index (PASI) score was done prior to therapy, at mid therapy and at end of therapy (PASI final). Results: No significant different in PASI final and in the percentage of reduction of PASI score between both groups (P value > 0.05) was found. However, a significant difference in the total number of sessions and the total cumulative UVA doses between both groups was found (P value < 0.001). Conclusion: Our study suggests reducing PUVA frequency and the cumulative UVA dose does not compromise the efficacy of PUVA, but it may improve its benefit/risk ratio.