NEW ORLEANS - Even if you don't use lasers in your day-to-day practice of dermatology, it's helpful to know the options and their limitations to prevent unnecessary referrals, Dr. Harvey Lui said.
"For those of you who do not use lasers, hopefully you can learn which things those of us who do lasers can help you with and things we cannot," Dr. Lui said at the annual meeting of the American Academy of Dermatology.
If the question is whether to use laser treatment for pigmentation disorders, the answers vary from yes to maybe to no.
As a general guide, the depth of the dyspigmentation makes the difference with lasers, so Dr. Lui addressed their use for epidermal, mixed epidermal-dermal, or dermal disorders.
Epidermal Dyspigmentation. Lentigines are the prototype epidermal pigmentation disorder. "Lasers are highly effective, relatively simple, [and work in] one to two treatments," Dr. Lui said. Although lasers are not the only treatment option (for example, there is cryotherapy), "I get more precise effects in my practice for darker-skinned patients."
Lasers are also useful to treat a seborrheic keratosis. The advantage with lasers is an ability to target each spot to be cleared, Dr. Lui said.
In contrast, a Becker's nevus does not respond very well to laser treatment, "even though pigmentation is right there in the epidermis just begging to be removed," said Dr. Lui, medical director of the Skin Care Centre and head of the department of dermatology and skin science at the University of British Columbia, Vancouver. "There was some initial excitement using fractional photothermolysis, but I don't think that has panned out over time."
Lasers are not ideal for an epidermal nevus either, Dr. Lui said, due to a higher recurrence rate. However, he added, "in a highly motivated patient, I might do a test spot first."
A high recurrence rate and an unpredictable response are reasons to avoid laser treatment for café au lait macules, Dr. Lui said. Smaller lesions tend to respond the best. He advised caution, because there can be some paradoxical darkening in these patients.
Mixed Epidermal-Dermal Dyspigmentation. Expect a variable response to lasers for melanocytic nevi. "The best response is with small, junctional nevi." Use the highest fluence possible, Dr. Lui advised. An unknown long-term risk and incomplete pigment removal that can lead to problematic lesions are considerations. "Tell the patient that if the pigment does not completely clear, we are going to cut it out. You don't want to leave them with a lesion that meets one of the ABCD criteria [that could develop into melanoma someday]," Dr. Lui said.
Congenital melanocytic nevi may respond to a normal-mode ruby laser, but again, the long-term risk is unknown.
Dr. Lui generally does not recommend lasers for melasma. "The bottom line is that melasma will reliably darken with lasers. You can bet on it." Initial excitement about fractional lasers did not pan out, he added.
Dr. Lui also cautioned against lasers for postinflammatory hyperpigmentation. "A laser usually generates more postinflammatory hyperpigmentation. It's just a vicious circle, so the bottom line is 'Don't go there.' " Instead, convince your patient to be patient. "The best treatment is often time, and it's the cheapest, too."
Dermal Dyspigmentation. Nevus of Ota and nevus of Ito, which are more common in Asian patients, feature an excellent responsiveness to laser treatment, Dr. Lui said. "These are life-transforming types of procedures you can do for patients. This is why I became a doctor."
Lasers also are appropriate for treatment of Hori's macules. These often look like lentigines, Dr. Lui said. To distinguish between the two types of lesions, look for a blue-gray color (as opposed to a brown color with lentigines) and lesions that appear smudgy rather than well delineated.
Lasers can be used to treat blue nevi, but caution is advised, Dr. Lui said.
Dr. Lui said that he had no relevant financial disclosures.