Dermatology Associates of the Bay Area
UVB phototherapy is a form of phototherapy for the treatment of psoriasis.
Natural sunlight emits a wide range of ultraviolet (UV) rays of different wavelengths, including UVA, UVB and UVC rays. UVB rays have been found to penetrate the skin and slow the growth of new skin cells, which can reduce the redness and flakiness of psoriasis lesions.
UVB phototherapy is particularly effective with guttate psoriasis. Generalized plaque psoriasis may require more treatments.
Although UVB rays can be obtained through sunlight, it is safer and more effective to use a specialized light that can control the duration and intensity of UVB ray exposure. Treatment involves exposing affected areas of skin to the UVB light source for a specific length of time on a regular schedule. The UVB light may be used in the doctor's office or at home with a home phototherapy unit obtained by prescription.
There are two types of UVB light treatments, broad band and narrow band. Narrow band UVB emits a limited range of UVB light compared to broad band UVB lights. Several studies have shown that narrow-band UVB can clear up psoriasis lesions faster and provide longer remissions than broad-band UVB. Your doctor will recommend a UVB light suited to your particular needs
During treatment clothing is removed as necessary to expose the affected skin to the light. Exposure time is based on the individual's own skin response and should be just long enough to create a very slight redness.
Treatment is usually repeated 3 to 5 times per week until the lesions clear. After as many as 25 or more treatments to get the psoriasis under control, maintenance therapy with less frequent treatments may be recommended.
Psoriasis symptoms may temporarily worsen for a short period following UVB phototherapy, but these reactions tend to lessen with successive treatments.
UVB phototheray may be combined with other psoriasis treatments, such as Soriatane® or biologics, to increase effectiveness and reduce the amount of medication required.