For Psoriasis, Laser Treatment Looks Promising
May 25, 2000 -- Lasers may be the wave of the future for treating the
irritating skin disorder known as psoriasis. Researchers have found that
zapping the scaly red patches even just once can get rid of them and is much
safer than the standard therapy of sitting in a box of ultraviolet light.
Psoriasis is a red, scaly rash that most commonly occurs on the elbows,
knees, scalp, and genitalia, although it can affect many other areas of the
body. It is most often first diagnosed in people in their 20s but it can occur
in children less than 10 years old. The rash usually comes and goes and can be
brought on by several factors including cold weather, stress, skin trauma, and
certain drugs. Most cases of psoriasis can be treated with steroid skin creams.
However, more severe cases often require exposure to intense ultraviolet rays,
Although this light therapy is very effective, it exposes patients to
damaging ultraviolet rays, much like sitting out in the sun. So researchers
have been hunting for a way to treat people with psoriasis without having to
damage their skin and increase their chance of getting skin cancer.
Compared with traditional phototherapy, the handheld laser is able to focus
the energy directly on the areas of the skin with the rash and spares the
surrounding skin from unnecessary radiation exposure, says study co-author
Charles R. Taylor, MD. This reduces short-term side effects like burning or
itching and long-term effects like wrinkling and cancer, he adds. Taylor is an
assistant professor of dermatology at Harvard Medical School in Boston.
Taylor and colleagues evaluated the laser in 13 patients with four or more
psoriasis patches. Each patch was given several doses of laser radiation --
anywhere from one to 20 treatments -- during the 10-week treatment period.
High doses of radiation produced significantly better results than medium or
low doses. Four months later, areas that were treated with medium or low doses
all had recurrences. Areas that were treated with high doses remained in
remission, even after a single treatment, although blistering was common. The
results are published in the May issue of the journal Archives of
Doctors say laser treatment is unlikely to replace phototherapy in psoriasis
management. "Laser treatment appears to be effective for resistant
cases", but it's probably not worth the cost for mild or moderate cases,
says Harold Brody, MD, clinical professor of dermatology at Emory University
School of Medicine in Atlanta.
Like the laser, phototherapy also uses ultraviolet light to clear psoriasis
patches. "Dermatologists often have a light box, mounted on the back of a
door, that emits different wavelengths of ultraviolet light," Brody tells
WebMD. "Patients simply stand in front of it at prescribed intervals,
usually after taking an oral drug called psoralen." The drug increases the
effects of light on the skin.