Narrow-spectrum medium-wave ultraviolet therapy is the most advanced skin phototherapy method in the world, it uses the peak 311nm narrow-spectrum medium-wave ultraviolet light wave, concentrating the strongest part of the biological activity of ultraviolet light to act directly on the affected area of the skin, while filtering out the bad band of ultraviolet light harmful to the skin, with little side effects, acting on the skin stratum corneum, short onset time and fast results. It is a purely physical treatment. Treatment principle: Medium-wave UV with wavelength of 311nm can be mostly absorbed by epidermal tissues, thus having significant biological effects on skin and other tissues. UV has good drying, sterilization, anti-inflammatory effect, direct killing effect on bacteria or virus in superficial tissues, accelerating blood circulation, analgesia, promoting epithelial regeneration, so the use of UV irradiation treatment can directly kill herpes virus to prevent secondary bacterial infection, promote blister absorption, pain relief, accelerate the repair and healing of skin lesions, thus playing a good therapeutic role. The study also found that UV irradiation can significantly inhibit the activity of antigen-presenting cells such as epidermal Langerhans cells, reduce inflammation, improve local blood circulation, promote the increase of melanin granules, promote rash healing and relieve pain, etc., and there are few adverse reactions, and the treatment is simple and safe. Treatment diseases: Vitiligo, psoriasis, atopic dermatitis, pityriasis rosea, eczema, baldness, pemphigoid granuloma, neurodermatitis, atopic dermatitis, palmoplantar pustulosis, pityriasis rosea, parapsoriasis, chronic skin ulcers, etc. Treatment protocol: Radiation therapy is divided into total body irradiation and local irradiation, depending on the type of disease. Treatment interval is 2 to 3 times per week. The increase in dose (duration) and proportion of treatment should be determined by the frequency and response to treatment. Treatment Precautions: Use with caution in pregnant women. Use with caution if you have a history of skin tumors or radiation therapy. Treatment precautions: 1. Remove surface scales from lesions by bathing for 15 to 20 minutes prior to irradiation; 2. Protect the area around the lesions by covering or using sunscreen during irradiation; 3. Avoid photosensitive foods and medications as much as possible during the treatment period; 7. Some lesions may appear to worsen briefly before the condition improves.