Phototherapy is the use of the sun by itself to treat a condition such as Mycosis fungoides and to treat acne. This treatment can be done by the use of sunlight or artificial light. Phototherapy has started to be used more commonly in states that have little sunlight; because it has recently been proved that it helps with seasonal affective disorder. It also has been found that it helps with delayed sleep phase syndrome.
Photo chemotherapy is the combined use of drug and exposure to the sun to help improve treatment. This includes vitiligo, and dermatitis. The most common form of treatment is known as PUVA therapy. PUVA is psoralen with long wave UVA radiation. However, PUVA is most commonly used on older people due to risks on maturing bone structures. Treatment can be anywhere from every day to twice a week. Treatment length also varies in correspondence to the age and reaction of the patient to treatment.