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Ultraviolet light treatment

Ultraviolet light is a treatment for a number of skin conditions including a type of skin cancer called T cell lymphoma. One type of UV treatment you might have for cancer is called PUVA (psoralen plus ultraviolet A). 

What is ultraviolet light treatment?

The sun produces a number of different ultraviolet UV rays each with their own wavelength. Ultraviolet A (UVA) is one of the rays, or wavelengths, produced by the sun. By combining it with a drug called psoralen it can help with some skin conditions including some skin cancers. This treatment is called PUVA. This is psoralen and UVA.

You might also hear ultraviolet light treatment called phototherapy.

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:

  • eczema
  • psoriasis
  • vitiligo
  • 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 your doctor says you can. And tell them about any medicines, herbal remedies or vitamins you are taking. 

PUVA for T Cell lymphoma of the skin

For T cell lymphoma of the skin you might have PUVA treatment 2 to 3 times a week for about 4 months (20-30 treatments). 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 care

Eye protection is very important. You must wear UV400 standard eye protection sunglasses for 24 hours from the time of taking your psoralen tablets. You need to wear sunglasses indoors as well as outside.

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:

  • sunlight
  • daylight
  • neon light
  • light through a window

Skin care

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.

Feeling sick

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.

Last reviewed: 
17 Aug 2018
  • Principles and practice of oncology (10th edition)
    VT De Vita, S Hellman and SA Rosenberg
    Lippincott, Williams and Wilkins, 2015

  • British Association of Dermatologists and British Photodermatology Group guidelines for the safe and effective use of psoralen–ultraviolet A therapy 

    T Ling and others 

    British Journal of Dermatology 2015 Volume 174, pages 24-55

  • Guidelines for phototherapy of mycosis fungoides and Sezary syndrome: A consensus statement of the United States Cutaneous Lymphoma Consortium

    E Olsen and others 

    Journal of the American Academy of Dermatology 2016 Volume 74 number 1 pages 27-58

  • Standards for genital protection in phototherapy units.
    FR Abdulla and others
    J Am Acad Dermatol. 2010 Feb;62(2):223-6. 

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact with details of the particular issue you are interested in.