Efficacy of 308-nm excimer light for Japanese patients with psoriasis.

Ultraviolet irradiation therapy, including psoralen and ultraviolet A therapy and narrow-band ultraviolet B (310-312 nm) therapy, is a widely used and highly efficient treatment modality for psoriasis. Therapy with 308-nm excimer light has been reported to be effective for the treatment of psoriasis vulgaris. To evaluate the efficacy of 308-nm excimer light therapy for Japanese psoriasis patients, seven patients (six men and one woman) with plaque-type psoriasis were treated with 308-nm excimer light at 7-14-day intervals. The Psoriasis Severity Index (PSI) was calculated for individual plaques in order to assess the effectiveness of the therapy. A 74.9% mean improvement in the PSI was observed after 10 treatment sessions. These results suggested that targeted irradiation with 308-nm excimer light leads to rapid and selective improvement in plaque-type psoriatic lesions without unnecessary radiation exposure to the surrounding unaffected skin.