PUVA Photochemotherapy
Photochemotherapy is a treatment that combines light and medication. In the case of PUVA, the light is a specific wavelength of UV light called UVA. UVA is used in combination with a medication known as a psoralen (the ‘P’ in PUVA). The psoralen can be taken as a tablet, rubbed on your skin, or added to a water bath.
How does it work?
PUVA works by psoralen making the skin sensitive to UVA light, allowing it to penetrate the deeper layers of the skin. Without the psoralen, UVA light would not be so effective.
When is it used?
PUVA may be recommended by your healthcare team if you have severe or widespread psoriasis.
How is it administered?
You will be given protective equipment before your PUVA treatment starts. This will protect more delicate areas of your body, such as your eyes. You will be asked to lie under or stand next to a UVA light source. The treatment booth often looks like a sun bed.
Your healthcare team will have decided on how much UVA you need (the strength of the UVA light, and how long it will last) based on the severity and type of your psoriasis. PUVA is normally administered 2–3 times a week, for several months. Your healthcare team will decide how often and for how long you need PUVA, which may be until your psoriasis improves.
Advantages and disadvantages
PUVA is an effective form of treatment and can lead to relatively long-lasting periods without the need for repeat treatment.
Some people who take the psoralen as a tablet may experience side effects including nausea. However, this can be avoided if your psoriasis is localised, by applying the psoralen topically to the affected areas.
PUVA is associated with an increased risk of skin cancer (in the same way that years of exposure to the sun increases your risk). Because of this increased risk, your healthcare team may limit the total amount of PUVA you have. The risk is thought to be greater if you have pale skin, or if there is a history of skin cancer in your family. With PUVA, there is also a slight risk of burns to the skin (similar to sunburn) and of premature ageing of the skin. This is due to the effect of the UV light on your skin, and is the same as the effects of too much exposure to direct sunlight.
If you have any questions about PUVA, you may want to discuss them with a member of your healthcare team.