Disseminated superficial actinic porokeratosis: appearance associated with photochemotherapy for psoriasis.

A patient with chronic psoriasis treated with psoralens plus ultraviolet A (PUVA) developed characteristic lesions of disseminated superficial actinic porokeratosis (DSAP). Since other processes associated with ultraviolet irradiation, including epidermal dysplasia, actinic keratoses, squamous cell carcinomas, and keratoacanthomas, have been reported to result from PUVA, it is possible that her DSAP lesions were induced by this therapy.