PUVA is an acronym that stands for “Psoralen + UV-A Light.” Psoralen makes the skin more sensitive to UV-A light, or more able to absorb this particular light wavelength, which has the effect of beating back psoriasis.
The steps to administering one “dose” of PUVA treatment are, as you might expect:
- Psoralen is taken by the patient either orally or via a skin cream.
- 2 hours later, specific portions of the skin are exposed to UV-A light.
The treatment can take as long as 48 hours to take effect and is (or certainly should be) done under a physician’s supervision. Going through this treatment more than every other day is highly discouraged.
Typically major differences can be observed after about 10 weeks of treatment. Light and psoralen dosage can be altered if, after about 10 weeks, there is no visible improvement. If the patient’s psoriasis worsens or if there is an excess of harmful side-effects, then the doctor in charge will most likely suspend the treatment.
Most people who go through this regimen (upwards of 80%) report drastic improvements in their psoriasis. However, as you might imagine, PUVA is inherently hard on the skin. In particular, UV-A light has been known to promote skin cancer. It was once thought that only UVB rays could cause skin cancer, but recently it was discovered that UVA and UVB light each cause skin cancer in their own special ways.
Note: any kind of therapy that combines chemical and light (such as PUVA) can also be called “photochemotherapy.” Photochemotherapy is sometimes used to treat skin cancer.
