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.