An actinic keratosis or solar keratosis is a rough, scaly patch of skin caused by years of exposure to the sun. It most commonly develops on the face, ears, scalp, neck, forearms or the backs of the hands. An actinic keratosis takes years to develop and usually appears in older adults.
Actinic keratosis is less than in an inch in diameter. It can be flat, slightly raised or be a bump. In some cases, it will be hard and wart-like. It can be pink, flesh-colored, red or brown. While most of these skin patches are harmless, they can sometimes become cancerous. There are several ways to treat an actinic keratosis including medications, surgery, freezing and photodynamic therapy.
What is photodynamic therapy?
Also known as PDT, photoradiation therapy, photochemotherapy or phototherapy, photodynamic therapy uses light in conjunction with special drugs to kill cancer cells. The drugs, which are called photosensitizing agents, only work after being exposed to certain kinds of light.
The doctor will cleanse the skin beforehand, taking especial care to remove any oils, for they would interfere with the treatment. He or she will then either apply the photosensitizing agent to the skin or inject it into the bloodstream to treat the actinic keratosis. In either case, it is eventually absorbed by the cancer cells. The patient will have to wait 30 to 60 minutes for the absorption process to take place. The doctor will then expose the treatment site to light that will cause the drug to react with oxygen and form chemicals lethal to the cancer cells. PDT might also help destroy the blood vessels feeding the cancer cells, and it might alert the immune system to cancer’s presence.
How Effective is PDT?
Studies have shown that PDT can be as effective as surgery or radiation therapy in treating some cancers or pre-cancers. It is less invasive than surgery and causes no long-term side effects. Similarly, once the treatment site heals, there is little or no scarring. The procedure does not take much time and can be done on an outpatient basis. Unlike radiation, PDT can be performed multiple times at the same site. Finally, PDT can be aimed at the treatment site very precisely.
Unfortunately, PDT does have drawbacks. The drugs used with it leave the patient quite sensitive to light for some time after the procedure, so they will have to take certain precautions after the treatment.
Who is a Good Candidate for PDT?
The best candidates are people with fair skin that have sun damage. People with darker skin are not good candidates, especially if their skin becomes discolored after light or laser treatments. People with a history of poor wound healing or extreme sensitivity to light are also not good candidates. PDT also can’t be used on people who are allergic to porphyrins or who have certain blood diseases including porphyria.
At Dermatology Associates, we provide photodynamic light therapy to those who need it. If you believe you have actinic keratoses, one of our clinicians will be able to assist you. Contact us today to schedule a consultation or if you have any questions.