SAN DIEGO – prior to undergoing the procedures.
“In the last year, in terms of hair removal, this has been the biggest change in my practice,” Mathew M. Avram, MD, JD, said at the annual Masters of Aesthetics Symposium.
R. Rox Anderson, MD, director of the Wellman Center for Photomedicine at Massachusetts General Hospital, and Melanie Grossman, MD, who practices in New York City, developed laser hair removal in the 1990s, and today laser hair removal stands as the most common laser treatment in medicine, said Dr. Avram, director of laser, cosmetics, and dermatologic surgery at Massachusetts General Hospital, Boston. He described it as “safe and effective in skilled hands,” requiring about six treatments. Indications are for hypertrichosis, hirsutism (sometimes in the setting of polycystic ovary syndrome), pseudofolliculitis barbae, pilonidal cysts, and gender reassignment surgery.
Laser hair removal works by the extended theory of selective photothermolysis. “You’re targeting by proxy,” Dr. Avram explained. “The laser targets eumelanin in darkly pigmented hairs, with the secondary target being the follicular stem cells. Pigment is a prerequisite for effective treatment. So if there is no pigment in the hair, with current technology, it’s not going to work.”
He advises clinicians to avoid a cookbook approach to fluences when performing laser hair removal. Even though higher fluences have been correlated with greater permanent hair removal, they are also more likely to cause unexpected side effects. “The recommended treatment fluences are often provided with each individual laser device for nonexperienced operators, but I would not recommend doing that,” he said. “You want to evaluate for the desired clinical endpoint of perifollicular erythema and edema. The highest possible tolerated fluence, which yields this endpoint, without any adverse effects, is often the best fluence for treatment.” In 2016, Dr. Avram and his colleagues published a paper that focuses on desirable and therapeutic endpoints when performing laser and light treatments (J Am Acad Dermatol 2016;74[5]:821-33).
The best candidates for laser hair removal are those with light skin color and dark hair. “The more pigment that’s in the hair, the more it’s going to absorb the energy,” he said. Coarse, thick hair responds better than thin vellus hairs, and blond, gray hairs do not respond. A new silver nanoparticle technology is being developed that may improve efficacy for people with blond or gray hair in the future. “Modest initial data showed that it works, but it requires several treatments,” Dr. Avram said.
A past president of the American Society for Laser Medicine and Surgery, Dr. Avram went on to note that laser hair removal is often delegated to nonphysicians and is the most common cause of lawsuits for laser injury. “The rates of lawsuits rise dramatically when delegated to nonphysicians,” he said. “They even rise higher when performed by nonphysicians without supervision such as in medi-spas. Some of the side effects when performed by nonexperienced users can include temporary hyperpigmentation and longterm hypopigmentation.”
One of his clinical pearls is to never perform laser hair removal on suntanned individuals (“you will get obvious, bizarre-appearing hypopigmentation,” he said) and to exercise caution in patients with darker skin types. “If you do a test spot, give it a couple of weeks to see if hyperpigmentation develops,” he advised. “However, their sun exposure may change, and the area you treat with a test spot may be different than the entire area you intend to treat, so don’t think that a test spot is going to guarantee a particular result. You also have to be aware of paradoxical hypertrichosis, where you get more hair growth rather than less.”
Laser hair removal is mandatory prior to neovaginoplasty surgery. Surgeons use skin from the penile shaft and the midscrotum to create the new vagina, Dr. Avram said, so all hair must be removed prior to surgery so that the inside of the new vagina will be free of hair.
“You can use laser or electrolysis for this,” he said. “Electrolysis takes a lot more treatments and is going to be much more tedious than laser hair removal.” Areas to be targeted include all hair on the scrotum and all hair on the penile shaft, plus one inch around the base. “In the perineum, you want to remove hair from the bottom of the scrotum to one inch above the anus in order to clear a 2.5-inch-wide strip,” he said.
For a phalloplasty, surgeons use skin from the underside of arm to create a urethra. This means that all hair should be removed from the crease of the wrist to 15-18 cm up the arm. “You treat the underside of the arm at 4 cm distally and 5.5 cm proximally,” Dr. Avram said. “It should be 15-18 cm in length, and you cannot have any hair that remains within the new urethra.”
To create a penis, surgeons use skin from the prone arm and around. This requires removing hair at 10 cm distally, 13 cm proximally, and 14 cm in length.
Dr. Avram emphasized the importance of patient and staff education and use of preferred pronouns when performing laser hair removal on patients prior to their gender reassignment surgery. “It requires an explanation that this requires multiple treatments and will not remove all hair,” he said. “You can work with an experienced electrologist for nonresponsive hair.”
Dr. Avram disclosed that he has received consulting fees from Allergan, Merz, Sciton, Soliton, and Zalea. He also reported having ownership and/or shareholder interest in Cytrellis, Invasix, and Zalea and intellectual property rights with Cytrellis.