Laser choices grow increasingly complex
Aspen, Colo. — Successful laser treatment of pigmented lesions and tattoos requires choosing the right tool for the job, an expert says.
Virtually any laser can target melanin, says George Hruza, M.D., a dermatologist in private practice in Chesterfield, Mo. “But some lasers work better than others.”
In particular, he says that targeting melanosomes requires pulse widths under one µs, the thermal relaxation time of the dermis.
“On the other hand, targeting epidermal lesions requires pulse widths under 1 ms,” because such pulses cause epidermal necrosis, he says.
Q-switched gets results
The standard of care for pigmented lesions and tattoos generally involves Q-switched lasers, whether ruby, alexandrite or Nd:YAG, Dr. Hruza adds. “They all work quite well.” Long-pulsed lasers also work for these indications, he says, but with a smaller safety margin. Somewhat similarly, he says that intense pulsed light (IPL) devices can lighten pigmented lesions. “However, I don’t believe these are the best way to treat individual lesions,” he says.
Ablative lasers remove pigment by removing the epidermis, Dr. Hruza says. Regarding fractional ablative lasers, he says, “I use them primarily for area treatments,” to remove hundreds of lesions at once. But for individual lesions, he prefers Q-switched lasers. “They allow for very specific targeting — one or two treatments and you’re done.”
Regarding specific clinical entities, Dr. Hruza says he would not treat a benign melanocytic hyperplasia with a laser without first confirming via biopsy that it is not lentigo maligna (LM). For café au lait macules, Dr. Hruza says, several treatments with a laser such as the Q-switched Nd:YAG or Q-switched ruby laser can lighten them quite effectively.
“But at least 50 percent of the time, they return,” Dr. Hruza says.