What is narrow band UVB (nbUVB) phototherapy?

Ultraviolet-B light (UVB) penetrates the skin and alters the immune system by reducing inflammation. UVB is in natural sunlight in small amounts. It can also be made artificially by lamps that put out broadband or narrowband UVB light.

This is not a cure, but can be a very effective treatment for many skin diseases.

Narrowband UVB is often more effective and safer than broadband. Treatment involves exposing the skin to UVB light from the specialized lamps at your doctor’s office. Treatments are done on a regular schedule to lessen side-effects while maximizing effectiveness.

Side effects of phototherapy

  • Your skin disease may get worse before it gets better.
  • Your skin may become red, itchy, or dry. This often gets better with regular treatments.
  • You may get a sunburn at any time during your treatment.
    • Tell your phototherapy nurse or doctor if you have redness of the skin, such as sunburn and itching. 
  • You may have flares of cold sores.
    • Tell our doctor if you get cold sores often. 
  • You are at higher risk of developing skin cancer. 
    • This risk is thought to be higher in people who have been treated long-term.
    • Exposure of the genitals to UV light, especially in men, can put you at higher risk of skin cancers.
    • You will have cover your genital area during treatment. 
    • UV light can harm the eyes. You will have to use protective eyewear during treatment.
    • UV light can lead to more freckles and sun spots.

Phototherapy treatments

It is often done at a doctor’s office or other approved medical facility. Your doctor will recommend how many days per week you will need to have treatments. Do not get treatments 2 days in a row.

Wear goggles to protect your eyes. Shield your genitals unless otherwise recommended by your doctor.

Your first treatment times will be very short, only a few seconds. Based on how your skin responds, treatment times will slowly get longer. It may take over 15 treatments before you notice your skin disease getting better.

Who should not use phototherapy?

Do not use phototherapy if you have a health condition that makes you sensitive to UV light or sunburn very easily, such as: genetic diseases or autoimmune diseases like lupus. Tell your doctor about all the medicines you take. Some can make you more sensitive to ultraviolet light. Also tell your doctor if you start new medicines during treatment.

Do not use a tanning bed in place of phototherapy

Tanning bed light is much different than UVB light. It is not effective for the treatment of psoriasis and puts you at higher risk for skin cancer. UVB is designed to treat skin disease while minimizing side effects. For this reason, the American Academy of Dermatology, the National Psoriasis Foundation, and the World Health Organization do not support the use of indoor tanning beds/booths for treatment of skin disease.

Last reviewed: 
August 2018

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