Targeted UV therapy in the treatment of psoriasis.

Ultraviolet (UV) light is an effective treatment for extensive psoriasis and some other inflammatory skin conditions. Because the predominant effect of UV is a local one (as opposed to a systemic effect on immunity), localized delivery of ultraviolet B radiation (UVB) may be a useful treatment for localized variants of psoriasis and other conditions. The article reviews the literature regarding use of localized UV therapy. A theoretical benefit of localized UV therapy is reduced toxicity compared with whole-body therapy. Practical benefits in psoriasis treatment include higher efficacy and more appealing cosmesis compared with topicals. The 308-nm excimer laser is effective for psoriasis with fewer UVB treatments and lower total UVB exposure than needed for total body UV treatment. Other methods of localized UV delivery include quartz lamps, hand-held home UV devices, and non-laser intense photo sources. Other conditions treated with localized UV include vitiligo and lichen planus. Localized UV therapy is a useful modality for the treatment of localized variants of psoriasis with growing use for other dermatologic diseases.