A randomized, controlled clinical trial comparing photochemotherapy with dithranol in the initial treatment of chronic plaque psoriasis

224 patients with widespread plaque psoriasis were randomly allocated to treatment with PUVA or dithranol. 103 of the 113 patients treated with PUVA (91.2%) cleared satisfactorily compared with 91 out of in patients treated with dithranol (82%). However, dithranol cleared psoriasis significantly faster than PUVA (20.4±0.9 days compared to 34.4±1.8 days). Photochemotherapy produced no evident short‐term adverse effects on the bone marrow, liver, or kidneys.