PUVA, UVB, psoriasis, and nonmelanoma skin cancer.

This article reviews the English-language literature on the risk of nonmelanoma skin cancer from phototherapy (UVB) or photochemotherapy (PUVA) in the treatment of psoriasis. The evolution of the debate on the carcinogenic potential of these treatment is discussed, particularly with reference to PUVA. Available data indicate that therapeutic UVB has a low risk of producing cutaneous cancers, with the possible exception of those on male genital skin. However, there is a definite cutaneous carcinogenic risk from oral PUVA. The major associated risk factors are reviewed. We provide recommendations for the assessment and treatment of patients to minimize this risk.