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Phototherapy for Psoriasis

Treatment Overview

Phototherapy is the use of ultraviolet (UV) light to slow the rapid growth of new skin cells and to decrease inflammation. This is helpful in treating psoriasis, which causes inflammation and the rapid growth of skin cells.

There are different types of UV light therapy.

  • Ultraviolet B (UVB):
    • UVB can be narrowband UVB or broadband UVB.
    • UVB can be used with a laser treatment for psoriasis (excimer laser). This can work well for treating smaller areas.
  • Ultraviolet A (UVA):
    • UVA can be used with psoralen. Psoralen is a medicine that makes your skin more sensitive to light. This treatment is called PUVA.

Sometimes UV therapy is used with other psoriasis medicines.

During phototherapy, you may stand in a booth that contains light tubes that give off UV light. Or you may have treatment with a smaller device if you have psoriasis in a limited area. Treatment is usually several times a week at first. Once your psoriasis is doing better, you may have it less often. Sometimes people may be able to do the treatment at home.

To keep yourself safe, carefully follow all of your doctor's instructions, such as protecting your eyes by wearing UV-blocking goggles during treatments.

What To Expect

After treatment, the skin is usually red or pink. Your skin may also be tender or itchy. Or you may feel stinging or burning. Some people get dark spots on the skin. This is more common in people with darker skin.

Why It Is Done

Phototherapy is an effective treatment option without the side effects that can happen with pills or other medicines. It may be used when psoriasis covers a lot of your skin. Or it may be used when medicines you put on the skin aren't working well. Sometimes it's used along with other treatments.

How Well It Works

Phototherapy can be an effective treatment for psoriasis. It can be used by people who are pregnant or breastfeeding.


Risks of phototherapy include:

  • Skin cancer. Exposure to UV light may result in skin cancer.
  • Skin damage. Exposure to UV light can cause sunburn and early aging of the skin. This includes wrinkles, loose skin, and age spots.
  • Cataracts and other eye problems. Protect your eyes with UV-blocking goggles during phototherapy treatments.
  • Other skin diseases getting worse. For example, exposure to UV light can reactivate a herpes infection.


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