Treatment of pityriasis rosea with UV radiation.

Twenty patients with symptomatic and extensive pityriasis rosea were treated with unilateral UV-B phototherapy in a bilateral comparison study. Five consecutive daily erythemogenic exposures resulted in substantially decreased pruritus and extent of disease greater than that on the untreated side in approximately 50% of the patients. Therapy seems to be most beneficial to patients receiving treatment within the first week of the eruption.