Phototherapy is a technique whereby various wavelengths of ultraviolet (UV) light are used to treat a wide range of different skin conditions, particularly eczema, psoriasis and vitiligo. Ancient physicians realised the healing power of the sun (heliotherapy) for some skin conditions, and modern phototherapy was developed initially to treat skin tuberculosis. In the 1970s, various cancer treatments were generated using the power of light, referred to as photochemotherapy. Phototherapy uses high-intensity UV light sources in specific wavelengths to treat conditions on the surface of the skin and in deeper layers of the skin.
There are two main types of phototherapy available.
Narrowband Ultraviolet B (NBUVB)
NBUVB is effective in treating several skin conditions, including eczema and psoriasis and uses only one of the wavelengths of light present in sunlight (hence 'narrowband'), specifically those found to be more beneficial in the treatment of skin conditions. For this reason, it is believed to be less harmful than exposure to sunlight, although some skin tanning or sunburn is possible.
Treatment is delivered ideally three times a week, 24 hours apart over 7-10 weeks.
Psoralen + UVA (PUVA)
Psoralen is a drug that increases the skin's sensitivity to UV light, which makes the light treatment more effective. A course of treatment of PUVA - also referred to as 'photochemotherapy' - lasts for around six months and treatment is required twice a week. PUVA treatment can also cause side effects such as freckles on the treated area of skin or sunburn.