Excimer laser slashes vitiligo treatment time

National report - In the treatment of vitiligo, the 308-nm excimer laser (PhotoMedex) achieves results as favorable as those of other phototherapy modalities in one-third the time, according to James M. Spencer, M.D.

The skin disorder is present in 1percent to 2 percent of the world's population and has no predilection for race.

"Vitiligo is characterized by localized loss of pigmentation, which is cosmetically distressing for patients," Dr. Spencer says. "The affected area is very sensitive to sunburn, and treatment with topical steroids and immune response modifiers (e.g., tacrolimus) alone is rarely successful. And the traditional psoralen with ultraviolet-A (PUVA) requires twice-weekly treatments for a year or longer, which is a major commitment (for the patient)."

Other modalities PUVA has an overall success rate of 50 percent, but that rate can be misleading because it represents an average of all skin types and all parts of the body, according to Dr. Spencer.

"Results vary with skin type and location of the disease," he says. "People with dark skin do better than people with fair skin. The face tends to do well, the hands tend to fail, and the rest of the body is in the middle." Narrow-band UV-B given twice a week for up to a year has a slightly higher reported success rate (53 percent) and a higher safety profile than PUVA, which is associated with the development of skin cancer on normal skin, he adds.

Physicians can almost promise African Americans with facial vitiligo that they will get their color back permanently, Dr. Spencer says.

"As for fair-skinned patients with vitiligo on the hands, the laser and other phototherapies will probably fail, and there is no plan B. Surgical procedures, though effective, can lead to scarring and textural changes," he says.

Excimer has advantages At Mt. Sinai, Dr. Spencer and his colleagues have been using the 308-nm excimer laser to treat patients with vitiligo.

"The excimer laser penetrates deeply enough to stimulate surviving melanocytes to migrate up hair follicles to the vitiligo patches on the skin," Dr. Spencer says.

The laser has practical and theoretical advantages over non-laser light treatments, according to Dr. Spencer.

"You shine the UV-B light onto only diseased skin and normal skin is spared exposure," he says. "The laser also has high energy, so treatment is more rapid. Theoretically, lasers may also penetrate more deeply, and a given dose is delivered more rapidly. For example, 100 joules given quickly may be more effective than 100 joules given slowly."

Although lasers deliver large doses quickly, they are limited by their small 2 cm-by-2 cm spot size, according to Dr. Spencer.

"Fortunately, most vitiligo is limited," he says.

Time slashed In a study published in the July issue of Dermatologic Surgery, Dr. Spencer and colleagues reported a 53 percent success rate in patients treated with the excimer laser twice weekly for 15 weeks, one-third of the time required for other phototherapy treatments. Success was defined as 75 percent or greater repigmentation, and patients were of all skin types and had vitiligo at all body locations.

"Just as with PUVA, dark-skinned people do better than light-skinned people," Dr. Spencer says. "The face responds well, the hands respond poorly, and the body's response is in the middle. But the excimer laser is as good as PUVA or narrow-band UV - in a fraction of the time - and normal skin is spared exposure." Dr. Spencer has also found that tacrolimus (Protopic, Fujisawa Healthcare) enhances the effects of the excimer laser.

A temporary "sunburn" is the only adverse effect of treatment, he says.