Actinic Keratosis - Common Skin Conditions: Skin Health

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Actinic keratosis

Actinic keratosis (AK) is a precancerous skin condition that appears as scaly pink or red-brown raised, rough patches on sun-exposed skin. Fair-skinned people are more likely than darker-complexioned individuals to develop AK. The condition can cause discomfort and itching, but its biggest danger is as a precursor to squamous cell carcinoma (see "Basal cell and squamous cell carcinoma"). The FDA has estimated that almost half of all skin cancers begin as AK spots. Most treatments can remove these crusty patches without scarring.

Treatment for actinic keratosis

Several methods exist for removing areas of actinic keratosis:

Cryotherapy. The standard treatment for AK is to freeze the area with liquid nitrogen. Inflammation, swelling, and occasionally blistering may occur. A small scab forms, and healthy new skin emerges as it heals.

Topical medications. A prescription cream containing the chemotherapy drug fluorouracil (5-FU) can be used once or twice a day for several weeks or on two consecutive days a week for several months. The cream removes the AK patch, but it causes sun sensitivity and, often, considerable discomfort. A topically applied drug called imiquimod is also very effective in treating AK spots. Imiquimod stimulates the immune system to release cytokines, chemicals that fight cancer cells and viruses. Imiquimod causes AK patches to become inflamed, crust over, and heal.

Deeper treatments. Widespread facial patches may warrant deeper treatments such as laser resurfacing (see "Laser and other procedures"), which vaporizes the epidermis and upper dermis, or a chemical peel, which dissolves the outer layers of the skin with a chemical solution. Laser resurfacing and chemical peels can involve local or general anesthesia. Depending on how deeply the skin is penetrated, they may result in considerable swelling. Still another effective treatment is electrodesiccation and curettage (see "Treating basal cell and squamous cell cancers."

Photodynamic therapy. This is a relatively new treatment, which uses light exposure to activate a therapeutic agent. In this case, the agent is Levulan, a topical solution of aminolevulinic acid, which occurs naturally in the body to process heme, a red blood cell component. First, Levulan is applied to AK spots, where it is converted into a light-sensitive molecule. Several hours to a day later, light or laser treatment activates the drug and destroys the AK cells. In a few days, the spots crust over and heal. Photodynamic therapy is appropriate when there are many AK spots on the face and scalp.

Last updated:	July 20, 2007