[Phototherapy for psoriasis; clearing lesions and maintaining lesion-free status].

Since time immemorial, sunlight has been used to treat a wide variety of skin afflictions. Consequently, probably on the basis of patients' experience and consequent experimentation with lamps, phototherapy has become an important dermatological treatment, particularly for psoriasis. The active component in sunlight proved to be ultraviolet (UV) radiation. Optimized UV lamps (type TL01) are now routinely used for clearing psoriatic lesions, after which therapy is stopped due to potential carcinogenic effects. The lesions reappear after a few months. Daily home treatment with low-dose UV radiation is a possible one to keep patients lesion-free; this leads to a marked reduction in the need for topical medications. This maintenance therapy can provide adequate suppression of this chronic skin disease.