Actinic keratoses (AKs) are considered pre-cancerous. They are common and are caused by long-term exposure to sunlight. AKs are most likely to appear after age 40, however, in places with year-round high-intensity sunlight AKs may develop in younger individuals. The most significant predisposing factor to AKs is fair skin and sun exposure which may have occurred in youth.
Chronic sun exposure causes skin cells to change size, shape, and the way they are organized. Changes in skin cells can become apparent when the skin becomes rough, scaly, or mottled, and develops bumps or small horn-like growths. AKs can turn into squamous cell carcinoma, a type of skin cancer.
Actinic keratoses are found on chronically sun-exposed skin such as the sides of the forehead, the ears, the scalp of bald men, and the backs of the hands. The typical AK lesion is a dry, scaly, and rough skin-colored to reddish-brown patch or bump on the skin. AK lesions may range from the size of a pinhead to larger than an inch. They are often sensitive.
An actinic keratosis can also appear on the lower lip and will dry and crack open. Any AK may at times seem to disappear for weeks or months and then return at the same place. They grow back if picked off.
Treatment of Actinic Keratoses
The basic types of treatment for actinic keratoses are cryosurgery by freezing with liquid nitrogen, topical chemotherapy, and photodynamic therapy involving a skin sensitizing medicine and certain types of light devices. Other surgical options that have been used include chemical peels and laser skin resurfacing.
Treatment should be fully and openly discussed with your dermatologist. After AKs are removed, the new skin must be protected from new solar damage by a program of skin care that includes sun protection.
Prevention of AKs should begin early in life as sun damage to unprotected skin begins in childhood. This puts the child at risk for actinic keratoses and skin cancer later in life. However, it is still beneficial to initiate prevention of new actinic keratosis lesions in adulthood.
The basics of prevention are:
- Avoid excessive exposure to sunlight during peak sunlight hours (10am to 4pm).
- Wear clothing that covers arms and legs, and wear a wide brimmed hat.
- Use a sunscreen with a sun protection factor (SPF) of 15 or higher daily.
- Apply at least 20 minutes prior to sun exposure for maximum sun protection.
- Select a broad-spectrum sunscreen that provides both UVA and UVB protection, and reapply sunscreen every 11/2 hours when outdoors, even on cloudy days.