ADAM Health Encyclopedia

Actinic keratosis

Definition

Actinic keratosis is a precancerous growth on the skin.

Alternative Names

Solar keratosis; Sun-induced skin changes - keratosis; Keratosis - actinic (solar)

Causes

Actinic keratosis is caused by sun exposure. It occurs most commonly in fair skin, especially in the elderly and in young people who have light skin.

Symptoms

• Rough and dry skin lesion
• Patch or growth on the skin
  • Limited to one area (localized)
  • Located on the face, scalp, back of the hands, chest, or other sun-exposed areas
  • Gray, pink, red (erythematous), or the same color as the skin
  • Begins as flat and scaly areas
  • Later develops a hard and wart-like or gritty, rough, and "sandpapery" surface -- may develop a horn-like texture

The skin lesion may be easier to feel than to see.

Exams and Tests

The health care provider makes the diagnosis based on the appearance of the skin growth. A skin biopsy may reveal any cancerous changes, if they occur.

Treatment

Because actinic keratoses are precancerous changes, have them examined promptly. Follow your health care provider's advice for treatment.

Growths may be removed by:

• Burning (electrical cautery)
• Freezing (cryotherapy)
• Surgery

Growths may also be treated with medications that cause the skin to peel or come off. More recently, lasers and other light sources have been used to treat actinic keratoses.

Creams such as 5-fluorouracil and imiquimod are used for people who have many lesions. These creams usually cause irritation and redness.

Outlook (Prognosis)

Actinic keratosis itself is benign, but it may develop into skin cancer. If left untreated, approximately 1% of actinic keratoses develop into squamous cell carcinoma.

Removal of the growth is usually effective.

Possible Complications

• Squamous cell carcinoma
• Irritation and discomfort of the skin growth

When to Contact a Medical Professional

Call for an appointment with your health care provider if areas of persistent roughness or scaliness develop in sun-exposed skin.

Prevention

Ways to prevent actinic keratosis:

• Reduce sun exposure and protect your skin from the sun.
• Wear protective clothing such as hats, long-sleeved shirts, long skirts, or pants.
• Try to avoid sun exposure during midday, when ultraviolet light is most intense.
• Use high-quality sunscreens, preferably with SPF (sun protection factor) ratings of at least 15. Pick a sunscreen that blocks both UBA and UVB light.
• Apply sunscreen at least 30 minutes before going out into the sun, and reapply frequently.
• Use sunscreen year-round, including in the winter.

de Berker D, McGregor JM, Hughes BR. Guidelines for the management of actinic keratoses. Br J Dermatol. 2007;156:222-230.