What is actinic keratosis?

Actinic keratosis is a skin disorder in which rough, scaly, or dry patches or lesions develop on sun-exposed parts of the body. These patches or lesions are precancerous, and if left untreated, there is a small risk that they can turn into a type of skin cancer called squamous cell carcinoma.

Who is at risk for actinic keratosis?

The following groups are at greater risk for developing actinic keratosis:

  • People with light or fair complexions
  • People with blond or red hair
  • People with blue or green eyes
  • People whose immune systems are weakened from illness or immunotherapy
  • Middle-aged and older people whose skin has been damaged by years of sun exposure

Actinic keratosis is very common and occurs in millions of Americans. The number of cases is growing because people are failing to take the proper steps to protect themselves from sun exposure.

What causes actinic keratosis?

The major cause of actinic keratosis is excessive sunlight (natural light such as the sun or artificial light such as a tanning bed). Long-term exposure to the ultraviolet rays in sunlight causes chemical changes in skin cells known as keratinocytes, which make up 90 percent of the epidermis (the outermost layer of the skin). These keratinocytes then undergo changes in their size, shape, and organization.

What are the symptoms of actinic keratosis?

An actinic keratosis (plural "keratoses") may appear as a scaly, raised, or rough area of skin. The keratosis can be pink, red, or brown; sometimes it is the same color as normal skin, but feels rough or dry to the touch. They are easier to feel than to see.

Actinic keratoses are more likely to develop on parts of the body that get the most exposure to the sun, such as the face, ears, neck, hands, and forearms. Peeling or cracking lips, especially the lower lip, after sun exposure might also be a sign of actinic keratosis.