Ultraviolet light treatment

Ultraviolet (UV) light is a type of light treatment.  Doctors use it to treat a number of skin conditions. These include a type of skin cancer called T cell lymphoma.

There are different types of UV light treatment. The most common type is UVB.

Another type of UV treatment you might have for cancer is called PUVA. This is less common. PUVA combines UVA light with a drug called psoralen. Psoralen makes your skin sensitive to light. You then stand in a cabinet which shines ultraviolet light on to your skin.

This page is about PUVA.

What is ultraviolet light treatment?

The sun produces a number of different ultraviolet UV rays, each with their own wavelength. Ultraviolet A (UVA) and Ultraviolet B (UVB) are both types of rays, or wavelengths. 

Doctors use UV to help with some skin conditions including some skin cancers. When using UVA, they need to combine it with a drug called psoralen as UVA would not work on its own. This treatment is called Psoralen ultraviolet light treatment (PUVA).

You might also hear ultraviolet light treatment called phototherapy.

Who can have Psoralen ultraviolet light treatment (PUVA)?

Doctors use PUVA to treat a type of lymphoma that affect the skin (cutaneous T cell lymphoma).

It is also a treatment for other non cancerous skin conditions such as:

  • eczema
  • psoriasis
  • graft versus host disease

How you have PUVA

You have PUVA as an outpatient at the hospital.

Before treatment

Your doctor or specialist nurse will talk to you beforehand. They will tell you how you will have treatment and exactly what it involves. Your nurse or doctor checks your skin before each treatment.

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. 

Having PUVA

You take the psoralen as tablets. You swallow it with food or milk. You wait for 2 hours for your body to absorb the psoralen. 

You remove your clothes from the area where you are having the treatment. Your doctor gives you goggles to protect your eyes. You might wear a visor to protect your face if it isn’t in the treatment area. 

You usually stand in a cabinet which shines ultraviolet light on to your skin.

The light treats the sensitised skin cells. You might have some tingling or heat in your skin. This is normal and not harmful.

How often do you have treatment?

For T cell lymphoma of the skin you might have PUVA treatment 2 times a week for up to 30 treatments. 

You might need future treatments if your skin gets worse again. Some people might have a repeat course of treatment, usually after a year or so.  You can't usually have more than 5 courses or PUVA over your lifetime. But sometimes, you might be able to have extra courses for your hands and feet.

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. The psoralen tablet makes you sensitive to the light. So eye damage can be caused by:

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

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.

Skin care

Psoralen makes the skin more sensitive to light. 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. Tell your doctor or nurse if you feel sick. They can give you anti sickness medicine. 


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.


You should 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 and increased freckling
  • 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.

  • 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

  • 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 patientinformation@cancer.org.uk with details of the particular issue you are interested in.

Last reviewed: 
04 May 2022
Next review due: 
04 May 2025

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