Consider skin of color when using pigment lasers

Portland, Ore. - Skin color can determine the best type of pigment laser to use, according to Ken Lee, M.D., a dermatologic surgeon at Oregon Health and Science University.

Dark skin has special needs "For most types of pigment in Caucasian skin, the Q-switched 532 nm ruby or alexandrite lasers work very well. They can cause the most amount of lightening, typically fading lentigines and freckles in one or two treatments," he says.

However, these lasers can cause hyperpigmentation or hypopigment-ation in darker skin. "In patients with darker skin, using a laser with a shorter wavelength can result in too much absorption by the natural skin pigment, which can cause hypopigmentation or too much lightening. These lasers should be used cautiously in Fitzpatrick skin types III and IV and should generally be avoided in types V and VI," Dr. Lee says. "The Q-switched 1064 nm YAG laser is safer in these darker skin types. Another concern in darker-skinned individuals is that you can get a rebound hyperpigmentation."

"This is especially important when using Q-switched lasers. Q-switched lasers for Caucasian skin are very effective because they are very powerful, but the same power that basically explodes the pigment will incite an inflammation and a rebound hyperpigmentation in darker skin," he explains.

According to Dr. Lee, when treating dark skin, dermatologists must be gentle, and should consider lower energies and more treatments. Dermatologists need to use hydroquinone both before and after the laser treatment. Additionally, using long-pulsed lasers and intense pulsed light devices can be a safer way to treat pigment in darker-skinned individuals, as these devices cause less trauma than the Q-switched lasers. The same precautions apply to the treatment of melasma in all skin types. Often, overly aggressive laser treatments may worsen melasma by inducing rebound hyperpigmentation.

Other treatment modalities, such as topical therapy and chemical peels, should be considered.

Removing tattoo pigments Dr. Lee says that today's tattoos can be difficult to remove.

"Patients should be forewarned that professional tattoos can some-times take more than 10 treatments, and even after numerous treatments, you may not have perfectly normal- appearing skin," he says.

He adds that today's tattoos have more exotic colors and a higher concentration of ink than tattoos done years ago. This makes them more difficult to remove. Additionally, the ink used today can result in paradoxical darkening when attempting to remove the tattoo.

"When you treat with the laser, the tattoo can actually turn darker or even black. The colors that you need to be particularly aware of are earth tones and skin colors," he says. " The ink used for these colors may have iron in it, and the use of the pigment laser ... can cause a paradoxical darkening."

He notes that skin-colored tattoos are often used for cosmetic reasons, such as for eyebrows or for lip liner. For these tattoos, artists often blend several earth tones together to make the tattoo look more natural.

Additionally, very bright tattoos can contain titanium dioxide, which also can lead to paradoxical darkening. When using a pigment laser for these tattoos, Dr. Lee recommends testing the treatment on a small spot to see if darkening occurs.