Types of UVB Therapy
One type of phototherapy that has been used successfully to treat psoriasis for more than 75 years is broadband (BB)-UVB therapy. As its name implies, BB-UVB is used to treat a large area of psoriasis by exposing the affected skin to a specific wavelength of UVB light.
A newer form of UVB therapy introduced in the United States in the 1990s that is commonly used to treat psoriasis is narrowband (NB)-UVB therapy. With this therapy, narrower bands of UVB wavelengths are administered to the affected skin, and studies have shown NB-UVB therapy to be more effective in clearing psoriasis than BB-UVB.
“Studies have shown that psoriasis patients treated with NB-UVB therapy had better results than those treated with BB-UVB, including more rapid clearing and better remission rates,” said Dr. Pariser. “While both therapies are generally well-tolerated, patients must be educated as to the potential long-term side effects of UVB – including an increased risk of skin cancer and premature aging – and protect their eyes by using goggles to decrease the risk of UVB-related cataracts that could form from prolonged exposure.”
Other minor side effects of BB-UVB therapy include redness, itching, burning and stinging. Burning also is a possible side effect of NB-UVB, and Dr. Pariser noted that, although not commonly reported, there have been instances of skin blistering after exposure to NB-UVB. In addition, neither BB-UVB nor NB-UVB therapy are known to cause birth defects or disrupt a pregnancy and can be prescribed to women during pregnancy or while attempting to conceive.
Studies examining the use of and long-term safety of UVB therapy in children are limited, but Dr. Pariser explained that this therapy could be considered as a second option in selected children whose psoriasis does not respond to topical therapy as long as the light therapy is closely monitored by a dermatologist.
In some cases, UVB therapy is effective when used by itself to clear psoriasis, but dermatologists commonly use this therapy in combination with topical or systemic medications. Dr. Pariser emphasized that the decision to use combination therapy should be made on a case-by-case basis and should be tailored to meet individual patients’ needs.