Phototherapy

Treatment with light, including sunlight, ultraviolet light, blue light, or lasers. Moderate exposure to sunlight is the most basic form, and is often helpful in treating psoriasis. PUVA combines the use of long-wave ultraviolet light with a psoralen drug, which sensitizes the skin to light. This is used to treat psoriasis and other skin diseases such as vitiligo. Psoriasis may also be treated using short-wave ultraviolet light, sometimes combined with the application of coal tar. Visible blue light is used to treat neonatal jaundice (see jaundice, neonatal), which is due to high levels of the pigment bilirubin in the blood. In phototherapy, bilirubin is converted into a harmless substance that can be excreted. To maximize exposure, the baby is undressed and placed under the lights in an incubator to keep him warm.