ultraviolet light therapy ultraviolet light therapy ultraviolet light therapy or ultraviolet phototherapy is a treatment for psoriasis, atopic skin disorder, vitiligo and other skin diseases. ultraviolet light therapyother namesutraviolet phototherapyicd-10-pcs6a8icd-9-cm99.82meshd014467 there are two main treatments: uvb that is the most common, and puva. there are four uvb types of lamps: fluorescnt broad-band uvb that emit 280-330 nanometer, fluorescent narrow-band that emit 312 nanometer, excimer that emit 308 nanometer and led that emit 290-300 nanometer. puva means uva + psoralen. it consists of irradiation of the skin with the uva ultraviolet light, from a fluorescent bulb or led lamps. tanning beds are used both in dermatology practices for the treatment of cosmetic skin conditions (such as psoriasis, acne, eczema and vitiligo) and in indoor tanning salons for cosmetic tanning. typical treatment regimens involve short exposure to uvb rays 3 to 5 times a week at a hospital or clinic, and repeated sessions may be required before results are noticeable. almost all of the conditions that respond to uvb light are chronic problems, so continuous treatment is required to keep those problems in check. home uvb systems are common solutions for those whose conditions respond to treatment. home systems permit patients to treat themselves every other day (the ideal treatment regimen for most) without the frequent, costly trips to the office/clinic and back, mainly when the area is small, and the price of the lamp is low. side effects side-effects may include itching and redness of the skin due to uvb exposure, and possibly sunburn, if patients do not minimize exposure to natural uv rays during treatment days. cataracts can frequently develop if the eyes are not protected from uv light exposure. to date, there is no link between an increase in a patient's risk of skin cancer and the proper use of narrow-band uvb phototherapy. "proper use" is generally defined as reaching the "sub-erythemic dose" (s.e.d.), the maximum amount of uvb your skin can receive without burning. certain fungal growths under the toenail can be treated using a specific wavelength of uv delivered from a high-power led (light-emitting diode) and can be safer than traditional systemic drugs.