Actinic Keratosis

Actinic keratosis (ak-TIN-ik ker-uh-TOE-sis) is a rough, scaly patch on your skin that develops from years of exposure to the sun.

Actinic Keratoses (AKs) are considered the earliest stage in the development of skin cancer. They are common growths of the epidermis (outermost layer of the skin), and are caused by long-term exposure to sunlight as far back as childhood. AKs are most likely to appear after age 40, however, in geographic areas with year-round, high-intensity sunlight such as Florida and southern California, AKs may be found in persons as young as the teens and twenties. Half of all older, fair-skinned persons who live in hot, sunny areas have AKs.

Chronic sun exposure causes skin cells to change size, shape, and the way they are organized. The skin cells affected in AKs are the keratinocytes. Keratinocytes are the tough-walled cells that make up 90 percent of the epidermis and give skin its texture.

AKs are caused by changes in keratinocytes and the skin becomes rough, scaly, or mottled; and occasionally, the skin may develop bumps or small horn-like growths. Further changes in cell growth can turn AKs into squamous cell carcinoma, a type of skin cancer.



Actinic Keratosis

Eczema/Atopic Dermatitis

Herpes Zoster



Seborrheic Keratosis

Skin Cancer


AKs are found on chronically sun-exposed skin, most commonly on a fair-skinned person, middle-aged or older. They can be found on any skin surface but are commonly found on the face, sides of the forehead, ears, the scalp of bald men, and the back of the hands. The typical AK is a dry, scaly, rough textured, skin-colored to reddish-brown patch, or slightly elevated “bump.” An AK may range from the size of a pinhead to larger than a quarter. Skin-colored AKs may be easier to feel than to see and may be noticed more by the touch because they have a sharp, hard scale and feel like sandpaper. They are often sensitive or “touchy.” Wrinkling, furrowing, and other signs of sun damage may be present with an AK. An AK at any location may seem to disappear at times for weeks or months, and return in the same place. If they are picked off, they grow back.

If an AK undergoes rapid upward growth, it becomes a “cutaneous horn” which gets its name from its appearance, as it can look like a horn of an animal. The size of a horn may vary from a pinhead to a pencil head eraser; and its shape may be straight or curved. The ear is a common site for a cutaneous horn. Sometimes, a skin cancer can hide below a cutaneous horn. An AK can also appear as a diffuse, scaling lesion on the lower lip that dries and cracks open.

Treatment should be fully and openly discussed with your dermatologist. After actinic keratoses are treated, the new skin must be protected from solar damage by a program of skin care that includes the use of regular sunscreens and sun protection.


Prevention of AKs should begin early in life. Sun damage to unprotected skin begins in childhood and puts the child at risk for actinic keratoses and skin cancer later in life. However, it is never too late to initiate prevention of new actinic keratosis lesions in adulthood.


  • 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 30 or higher daily, and apply it 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 1.5 hours when outdoors, even on cloudy days.