Photodynamic therapy removes skin lesions

Dr. Patrick Teer uses photodynamic therapy to treat precancerous skin spots.

Patients with multiple lesions from sun damage can choose an alternative to the liquid nitrogen therapy dermatologists often use to remove spots before they become cancerous.

Photodynamic therapy is an FDA-approved treatment that combines a photosynthesizing solution with a specialized light source to eliminate actinic keratoses, which can develop into squamous cell carcinoma — a common form of skin cancer. Dr. Patrick Teer, a board-certified dermatologist at the Dermatology Clinic of Jackson, said the treatment is generally for people with 15 or more lesions on their face or scalp.

"It depends on the degree of damage they have," Dr. Teer said. "It is really designed for the folks who have a whole lot."

Actinic keratoses are rough-textured, dry and scaly patches on the skin that are caused by exposure to ultraviolet light. They develop after years of sun exposure, generally after a patient is 40.

The sun spots are the most common precancer and affect up to 58 million Americans. Risk factors include a history of sun exposure; fair skin; blonde or red hair — especially when combined with blue, hazel or green eyes; a tendency to freckle or burn after time in the sun; and a weakened immune system.

With photodynamic therapy, physicians apply the topical solution Levulon Kerastick and wait up to two hours for it to incubate. Physicians then apply the Blu-U light treatment, which delivers a uniform dose over the entire treatment area for 17 minutes.

"It is a way to treat sun damage in a broad or field effect instead of individual lesions," Teer said.

Four to six weeks later, the patient returns for another round of treatment. After the second round, 70 percent of patients experience 100 percent clearance of actinic keratoses on their face.

Patients may experience slight burning, tingling or prickling sensations during the light treatment, and Dr. Teer said they must avoid exposure to sunlight for 40 hours after the procedure.

The benefits to photodynamic therapy include a low down time and a short visit to the dermatologist. Patients do not have to undergo multiple liquid nitrogen therapy procedures, and they do not have to take prescription creams over the period of several weeks that can cause extreme irritation. It also gives patients more options, and it is covered by insurance, Dr. Teer said.

"It adds to what we can offer patients to treat their precancerous sun damage."