Photodynamic therapy (PDT), the practice of irradiating a photosensitizing agent to damage cells, has a broad—and growing—range of indications. In dermatology, PDT is used to target precancerous and cancerous lesions, reduce the redness of rosacea, and destroy P. acnes bacteria and the sebaceous glands to clear acneic skin. In aesthetic medicine, PDT is also being used as a skin rejuvenation treatment.
“Early on, we noticed that when patients underwent PDT, there was an improvement in skin tone and texture,” says Michael H. Gold, MD, medical director of Gold Skin Care Center in Nashville, Tennessee. “For example, if we used intense pulsed light (IPL) with a photosensitizer, we saw incredible rejuvenation results and some collagen changes—more than we see with IPL alone.”
“The reason PDT improves skin tone and texture is because it targets sun damage on the skin, which is responsible for a lot of the signs of aging,” says Doris Day, MD, founder of Day Dermatology & Aesthetics in New York City. “So it’s not just that the skin looks better, the skin is better after PDT. It stimulates the natural wound repair process, which includes new collagen formation for younger, healthier skin.”
With so many tools for skin rejuvenation now available, the question is, where does PDT fit as a stand-alone aesthetic treatment?
One of the first considerations in patient selection for PDT skin rejuvenation is the presence—or lack—of actinic keratoses (AKs). “PDT with blue light is FDA approved for the removal of AKs on the face and scalp,” says Dr. Gold. “You will see a rejuvenation effect, but the patient has to have AKs to charge insurance, and you have to document the number of AKs and their locations. Once somebody starts talking about PDT with a device other than blue light—or blue light PDT for a patient who has no AKs—that is a cosmetic treatment.”
The most commonly used topical photosensitizer for photodamage and AKs is 5-aminolevulinic acid (sold under the brand name Levulan, DUSA Pharmaceuticals), which can be combined with blue light, red light, IPL or pulsed dye lasers (PDL) for vascular concerns.
For patients without AKs seeking skin rejuvenation, the two main criteria to consider when selecting among peels, PDT and resurfacing lasers are the health of the patient’s skin and their tolerance for downtime.
Todd E. Schlesinger, MD, director of the Dermatology & Laser Center of Charleston and the Clinical Research Center of the Carolinas in Charleston, South Carolina, considers PDT primarily for patients with photodamage-related AKs and/or skin discoloration. “A fair-skinned person who has a larger number of precancerous lesions or mottled pigmentation, such as multiple lentigenes or dark freckles on the face, is a great candidate for PDT versus laser alone,” he says. “If the patient’s skin is not elastotic, meaning they have a tremendous amount of wrinkling or they have very loose, thin skin, they are better served with ablative or nonablative laser resurfacing.”
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