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, incidence, and risk factors

Actinic keratosis is caused by sun exposure.

Risk factors for actinic keratosis include:

• Having fair skin, blue or green eyes, or blond or red hair
• Long-term, daily sun exposure (for example, if you work outdoors)
• Multiple, severe sunburns early in life
• Older age

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.

Signs 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)
• Curettage and electrodesiccation (scrapes away the lesion and uses electricity to kill any remaining cells)
• Excision (cutting the tumor out and using stitches to place the skin back together)
• Freezing (cryotherapy, which freezes and kills the cells)

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.

Expectations (prognosis)

Actinic keratosis itself is benign (harmless), but it may on rare occasions develop into skin cancer.

Removal of the growth is usually effective.

Complications

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

Calling your health care provider

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

Prevention

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) rating of at least 15. Pick a sunscreen that blocks both UVA and UVB light
• Apply sunscreen before going out into the sun, and reapply frequently
• Use sunscreen year-round, including in the winter
• Avoid sun lamps, tanning beds, and tanning salons

Other important sun safety facts to keep in mind:

• Sun exposure is intensified in or near surfaces that reflect light, such as water, sand, concrete, and areas painted white
• Sun exposure is more intense at the beginning of the summer
• Skin burns faster at higher altitudes

References

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

Ibrahim SF, Brown MD. Actinic keratoses. In: Lebwohl, ed. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009.