Actinic Keratoses
Actinic keratoses, or AK’s, are a common precancerous condition due to long-term sun exposure. They are seen on sun-exposed areas, such as the face, scalp, forearms, and hands. Actinic keratoses tend to “come and go”, and have a roughened, sandpaper-like texture. The lesions are typically red, pink, or light tan in color, usually develop slowly, and typically reach a size from one-eighth to a quarter of an inch.
Two to five percent of all actinic keratoses will progress, if untreated, into a squamous cell carcinoma, the second most common form of skin cancer. The effective treatment and prevention of actinic keratoses will minimize the risk of malignant transformation.
Treatment options for actinic keratoses include:
- Liquid nitrogen (cryosurgery). Liquid nitrogen is the most common treatment for actinic keratoses, particularly when there are a limited number of lesions. Liquid nitrogen is applied to the growth with a cotton-tipped applicator. No anesthesia is required, although slight stinging may be associated with the treatment. The treated area will become red, swollen, and irritated and a small blister may form. Over the course of the next several days, the lesion will crust and fall off. On occasion, an additional treatment may be necessary to completely clear the lesion.
- Topical treatments. Prescription creams and solutions are useful for treating regions that have multiple actinic keratoses. One advantage of topical medications is that they not only treat visible lesions, but also treat subclinical lesions that are small and not yet visible to the naked eye. One disadvantage of these creams is that they need to be used for several weeks, and they typically cause redness, crusting, and swelling of the treated areas.
Topical treatments include:
- 5-fluorouracil (5-FU) cream or solution. Brand names of this medication include Efudex Cream and Solution and Carac Cream. These medications contain 5-FU, an anti-cancer drug which attacks the precancerous cells. These creams may be used every day for 4 to 6 weeks, or may be used in a “pulsed fashion”, where they are used for only a couple of days per week for a longer treatment period.
- Imiquimod cream (Aldara). Aldara cream stimulates the body’s immune system to destroy the precancerous cells. The cream is typically applied 2-3 times per week for 6-12 weeks, based on the treatment response and level of irritation.
- Chemical Peels. This method uses Jessner’s Solution and/or trichloroacetic acid (TCA), which are applied directly to the skin. Over the following several days, the top layer of skin, including the actinic keratoses, sloughs off. The skin heals over the following 5-7 days. Some degree of burning is experienced with chemical peels.
- Laser Surgery. A carbon dioxide or erbium laser may be used to ablate actinic keratoses. Local anesthesia is typically required for this procedure, and skin pigmentation loss may be seen.
- Photodynamic Therapy (PDT). PDT involves applying a chemical (5-aminolevulinic acid) to the affected regions, followed by exposure to a strong light that activates the chemical and selectively destroys the actinic keratosis.
The most appropriate treatment option for actinic keratoses is chosen based on the number and distribution of lesions, in addition to patient preferences and responses to prior therapy.
Studies have clearly shown that sun avoidance and the daily use of a broad-spectrum sunscreen will help to reduce the number of existing actinic keratoses and will decrease the development of new lesions.
Informative Links for Actinic Keratoses: