"Many patients with dark skin go from doctor to doctor (being told) they can't have laser treatments because a lot of doctors believe they are unsafe on such patients. Lasers in the wrong hands are unsafe," says Min-Wei Christine Lee, M.D., M.P.H., dermatologic surgeon and director of The East Bay Laser & Skin Care Center, Walnut Creek, Calif. "There are many people who perform laser treatments who are not adequately equipped or trained to treat ethnic skin. Just because one knows how to treat a white person does not mean you could use those same settings on somebody with dark skin.
"However, many of the lasers have been greatly improved to the extent that anything that can be used on white skin can be used on ethnic skin if you understand the pathophysiology of ethnic skin, as well as the proper lasers, parameters, wavelengths and aftercare protocols to use," she says.Modalities Modalities that have been studied for treating acne in ethnic patients include blue light, intense pulsed light (IPL) and lasers, including the Smoothbeam (Candela). Other lasers that have been investigated for this purpose include the Aura 532 nm KTP and the Lyra long-pulsed Nd:YAG 1,064 nm (infrared), which have been combined into the Gemini KTP Laser System (Laserscope).
"It turns out that it's quite safe to use most of these treatment devices on ethnic skin," she says. "It's just that one must be careful about using lower fluences and probably fewer passes to avoid complications such as blistering, scars and hypopigmentation," Dr. Lee says.
The KTP green laser has proven especially successful with pulse durations and fluences of 20 ms and 6 J/cm2, respectively, 5 mm spot, for Fitzpatrick types V and VI skin (or 30 ms, 8 to 9 J/cm2 for type IV) versus 30 ms and 9 to 12 J/cm2 for Caucasians.
"The reason this laser works so well in acne is that it penetrates into the acne lesion and helps to kill the bacteria. Additionally, it helps dry up the active lesions and inhibit oil production in the sebaceous glands," Dr. Lee says. "It also helps improve the actual discolorations that acne leaves behind, as well as some of the scarring."
The combination of radiofrequency and IPL also holds promise for treating acne in ethnic patients. A recent test conducted by Dr. Lee showed that in a total of 50 patients with skin types I through IV, the Aurora DSR (Syneron) achieved 80 percent to 90 percent improvement in 90 percent of patients after six weekly treatments. Sebum production also decreased, while no side effects surfaced1.
Hypopigmentation Laser treatments for hypopigmentation generally prove more successful on ethnic patients than on Caucasians.
"Since ethnic skin usually contains a higher and denser concentration of melanocytes surrounding the hypopigmented areas, there is greater chance of 'recruitment' of active melanocytes by stimulating the surrounding cells to produce more melanin that migrates into the hypopigmented areas," she says. "The success of repigmentation treatments depends on either presence of surrounding active melanocytes, which are capable of being recruited, or underlying dormant residual melanocytes capable of being stimulated. If a patient has no melanocytes left, it doesn't matter what laser we use — we can't stimulate pigmentation."
In a study involving 15 patients with vitiligo, 20 with hypopigmented striae and 15 with hypopigmented scars, Dr. Lee achieved 50 percent to 70 percent repigmentation with 15 or fewer treatments of the 290 to 320 nm ReLume UV system (Lumenis). The study furthermore found the system allows clinicians to selectively deliver smaller cumulative UVB doses to localized areas while sparing healthy skin2.