May 26, 2005 Psoriasis Update
Laser Treatments for Psoriasis
A variety of light therapies can be used to treat psoriasis when medicated creams are ineffective or impractical to apply. However, a major problem with most light therapies is that they damage large areas of healthy skin during treatment sessions. What's different about laser treatment is that it targets only the affected skin. This allows the physician to aim higher doses at the lesions, shortening the treatment time and leaving your healthy skin intact.
If you have mild-to-moderate plaque psoriasis, in which distinct areas of skin are red and covered by silvery scales, you may be a good candidate for laser treatment. The two types of lasers used for psoriasis are the excimer laser and the pulsed dye laser. Here's an overview of both types:
Excimer laser treatment
The excimer laser, which emits ultraviolet light at a wavelength of 308 nanometers, was first approved for use in psoriasis in 2000. It works by reducing inflammation on a cellular level and decreasing the number of skin cells that grow too quickly.
The handpiece of an excimer laser shines a beam of light about the size of a quarter. The person operating the equipment, usually a dermatologist, directs the beam at the targeted plaques. Treatment sessions last just a few minutes each and must be spaced at least two days apart. Most patients need a total of 8 to 15 treatments, at a rate of about two a week. In one study, 85 percent of patients had skin that was clear or close to clear after 13 sessions.
Your skin may feel warm during treatment with an excimer laser, but treatments should not be painful enough to require anesthesia. Most side effects are mild and include redness, blistering and the formation of shallow ulcers that heal without scarring. There is a small risk of skin darkening or scarring.
It is not known how long the effects of excimer laser treatment last. In one study, all of the lesions came back after four months — except those that had received an extra-high dose of light that caused blistering. Other doctors report that for some people, remission can last for eight months or more. Excimer lasers are especially useful for treating resistant plaques on the elbows and knees.
Pulsed dye laser treatment
The light from a pulsed dye laser is absorbed by hemoglobin, the protein that makes blood red. Because of this property, pulsed dye lasers are used to remove enlarged blood vessels, red birthmarks and other blood-vessel abnormalities. In psoriasis, pulsed dye lasers work by destroying enlarged, dilated blood vessels in the lesions.
A treatment session with a pulsed dye laser usually lasts from 15 to 30 minutes. Treatment for psoriasis usually involves between four and six sessions, spaced three weeks apart. Many people say that the treatments feel as if a rubber band is being snapped against the skin. The most common side effect is bruising; there is also a small risk of scarring.
Not all lesions respond to treatment with pulsed dye lasers, but in one study, those that did remained in remission for up to 13 months. Lesions with vertically-oriented blood vessels may respond to treatment better than those with twisted blood vessels. A physician can determine blood vessel patterns.
Questions to ask your doctor:
Am I a good candidate for laser treatment?
How many treatments will I need?
What kind of results can I expect?
How much will the treatments cost, and will my insurance cover it? (Note: you may need to check with your insurance provider to find out whether treatments are covered)
