Ultraviolet light treatment is used to treat some cancers. Find out how it works.
What ultraviolet light treatment is
Treating skin conditions using ultraviolet light is called phototherapy or photochemotherapy. Ultraviolet light is a natural part of sunlight. It reduces inflammation of the skin. It can help to heal the skin and treat some skin conditions.
Psoralen ultraviolet light treatment (PUVA)
To have PUVA, you have a drug called psoralen to make your skin sensitive to light. You then have ultraviolet light shone on to the skin. PUVA might be used to treat types of lymphoma that affect the skin, such as cutaneous T cell lymphoma (CTCL).
It is also used for other skin conditions such as:
- graft versus host disease
How you have PUVA
Your nurse or doctor checks your skin before each treatment. You have the psoralen as a tablet that you swallow with food or milk. You wait for 1 or 2 hours for the psoralen to be absorbed.
You might need to remove all your clothes but you have goggles to protect your eyes and a visor if your face is unaffected. Your doctor then shines an ultraviolet light on to the treatment area. Or you might stand in a cubicle with light tubes that give out ultraviolet light.
The light treats the sensitised skin cells.
You might have some tingling or heat in your skin. This is normal and not harmful. Don't apply creams or perfumes before having PUVA, unless recommended by your doctor.
Tell your doctor about any medicines, herbal remedies or vitamins you are taking.
PUVA for T Cell lymphoma of the skin
You might have treatment 2 to 3 times a week for about 4 months (20-30 treatments) if you have PUVA for lymphoma of the skin. After this time it is hoped your skin will be clear or almost clear.
You might need future treatments if your skin worsens. Some people might have repeat treatment courses, usually after a year or so.
Side effects of PUVA treatment
As with all treatments, PUVA has some side effects. Psoralen is a photosensitiser. This means that it makes your skin and eyes very sensitive to light.
Your doctor gives you guidelines to follow after you have treatment. It's important to follow these to prevent serious side effects.
Eye protection is very important. You must wear UV400 standard eye protection sunglasses for 24 hours from the time of taking your psoralen tablets. So you need to wear sunglasses indoors too. You can get the sunglasses from chemists. If you don’t wear eye protection, you might have permanent eye damage, such as cataracts.
Because you have been sensitised to light, eye damage can be caused by:
- neon light
- light through a window
Psoralen makes the skin more sensitive to light. So you will burn more easily than usual in the sun, especially on the day you have treatment. It's very important to protect yourself from the sun.
- Don’t expose your skin or lips to sunlight or sun lamps for 24 hours after taking the psoralen tablets. Wear SPF lip balm and sunscreen.
- In sunny conditions use a sun block or high SPF sunscreen (SPF 30 and 4-5 star UVA protection) on all areas of skin exposed to light.
- Avoid sitting near windows because UVA can pass through glass.
- On treatment days make sure that all skin is covered by wearing long sleeved clothing, gloves, and enclosed shoes. You also need a wide brimmed hat to protect your face and head.
Psoralen may make you feel sick for a few hours after you take it. Try eating little and often.
You may have itchy skin for a few days after PUVA treatment. Check with your team but using non perfumed moisturisers after the treatment can help.
If you are pregnant
Doctors think that psoralen could cause birth defects, so you must not have PUVA treatment if you are pregnant. You should use reliable contraception throughout your course of treatment if there is any chance you could become pregnant.
Talk to your doctor or nurse about contraception before starting treatment.
Long term side effects
The long term side effects of PUVA include:
- ageing of the skin
- skin darkening
- an increased risk of other types of skin cancer
The skin cancer risk is higher in fair skin and after multiple treatment courses. Your doctor will discuss the risks, benefits and possible side effects of the treatment with you.