The authors present the results of a clinical study using an 308 nm excimer laser for treatment of chronic localized psoriasis. After assessment of the individual MED (minimal erythema dose), the patients were treated 6x (17 patients) or 10x (11 patients) with UVB radiation of wave length 308 nm. Individual doses varied within the range of 2-5multiples of MED. During 2-3-week treatment the authors achieved in the absolute majority of patients significant improvement of the clinical finding as apparent from the decline of the psoriatic score (PS) of the treated areas and illustrations. The patients were followed up as part of the study for 3 months after completed treatment. In the majority significant improvement of the clinical finding persisted at least for one month after termination of treatment. After an interval of 2-3 months following termination of treatment, gradual exacerbation of psoriasis developed, which however did not reach the pretreatment level. The excimer laser emitting UV radiation of wave length 308 nm is a new possibility of treatment of chronic localized psoriasis. Contrary to commonly used methods of conventional phototherapy, only psoriatic lesions are exposed toUV radiation and not the healthy skin. With regard to the greater resistance of psoriatic lesions to the effects of UV radiation in the described method supraerythematous doses may be used. The method makes it possible to shorten markedly the time needed to improve or cure the clinical finding and to reduce the whole body cumulative dose of UV radiation.

        Key words: excimer laser - psoriasis - UV radiation - phototherapy