What chemical peels lack in hype, they more than make up for with versatility and value, says Gary D. Monheit, M.D., associate clinical professor of dermatology and ophthalmology, University of Alabama, Birmingham.
"Chemical peels are the second most common aesthetic procedure performed in our offices, yet somehow we turn our back on them, as if they don't count. They're not as sexy as they were 50 to 100 years ago," Dr. Monheit says.
Nevertheless, "Chemical peeling remains the most popular, reliable and efficacious method of skin resurfacing," he says. "It's a safe, effective tool for epidermal growths, dyschromias, wrinkles, photoaging, fine lines and scars."As opposed to buying a new laser every four years for $150,000, chemical peeling is a tool that will continue to earn its keep in aesthetic practices, Dr. Monheit says. In fact, he says, chemical peels are enjoying a resurgence because laser and light devices often fail to live up to their hype.
"It's important to understand how the peel and the healing work — a chemical peel can be an expression of you rather than a commodity a patient will ask for," he says. "There are a number of technical variables that are controlled by the surgeon."
With lasers and light devices, "Most of us don't fully understand the balance between energy, voltage, the depth of delivery and other treatment parameters," Dr. Monheit says. "So if something happens that's not quite right, we have to call the laser detail salesman. Many times, they're the ones telling us what to do."
PEELS 101 Peels involve exfoliation achieved by applying chemicals to the skin, causing both destruction and inflammation. "And that stimulates new skin," Dr. Monheit says. Tools for superficial resurfacing include chemical preparations and microdermabrasion. For medium-depth resurfacing, the most commonly used tools include combination peels, manual dermabrasion, erbium lasers and some nonablative fractional lasers. Options for deep resurfacing include phenol peels and CO2 lasers.
"The depth of a peel depends on the chemical, concentration, what type of skin you're applying it to — is the skin heavy, oily and sun-damaged or fine and pristine?" Dr. Monheit says. Skin preparation regimens (such as application of exfoliants, retinoids, hydroquinone and/or microdermabrasion) and chemical peel application techniques also play a role. "Pick and choose what you want based on the condition and patient you're treating."
Regardless of the peeling agent, "The mechanisms are relatively the same — keratolysis, precipitation of proteins and epidermolysis," he says.
"TCA precipitates protein, which I believe is an important concept," Dr. Monheit says. Much like boiling an egg, he says, protein coagulates at the skin's surface. This produces a white frosting that can be followed clinically as an indicator of peel completeness.
However, Dr. Monheit says, "Never use TCA over 40 percent. It fell out of favor during the 1980s" because people were using higher concentrations that proved uncontrollable, causing persistent erythema and scarring.
"The one time we do use high-potency (80 to 100 percent) TCA is for focal treatment of acne scars," he says. This is performed by placing TCA into ice pick scars with a toothpick. "It's not a peel," Dr. Monheit says. Rather, the procedure destroys the epidermis and scar, which results in new collagen growth.