Lasers
Targeted UVB therapy
The Xtrac laser, which is approved by the FDA for psoriasis, emits a high-intensity beam of UV light that is very similar to the light delivered by narrow-band UVB units.
Xtrac's beam is small–less than 1 inch in diameter–and can be targeted at selected areas of the skin affected by psoriasis. Mostly, the laser is used to treat people with mild to moderate plaque psoriasis. This light treatment is recommended for those with less than 10 percent of the body covered by psoriasis or lesions localized to specific areas of the body.
How well an individual will respond to the treatment varies. It can take an average of four to 10 sessions to see results, depending on the particular case of psoriasis. It is recommended that patients are treated twice per week, with a minimum of 48 hours between treatments. Generally, the only side effect from laser treatment is a mild sunburn.
There is very little long-term data yet to indicate how long the improvement or clearance will last following a course of therapy. The Psoriasis Foundation has heard anecdotal reports from doctors that some patients' treated lesions will remain clear for eight months or more, but results will vary.
Pulsed dye lasers
Like the Xtrac laser, pulsed dye lasers are approved for treating chronic, localized plaque lesions. Pulsed dye lasers emit a different form of light than UVB units and the Xtrac laser.
Pulsed dye lasers destroy the tiny blood vessels that contribute to and support the formation of psoriasis lesions. They have been in use for approximately 15 years for removing unwanted blood vessels and birthmarks, such as port wine stains. Investigators first reported that psoriasis could be cleared with pulsed dye lasers in 1990.
Treatment with a pulsed dye laser reportedly feels like being snapped repeatedly with a rubber band. Treatment consists of 15- to 30-minute sessions every three weeks. For patients who respond, usually it takes between four and six sessions to clear the target lesion.
Side effects of pulsed dye laser treatments include a small risk of scarring. The most common side effect is a bruise that remains after treatment for a week to 10 days.
Updated December 2005
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