Actinic Keratosis (AK)

Actinic keratosis (AK), also known as solar keratosis, is one of the most common precancerous lesions of the epidermis (outer layer of skin). It is caused by long-term exposure to sunlight.

Chronic sunlight exposure alters the keratinocytes (cells that make up the majority of the epidermis) and causes areas of your skin to become scaly, rough, discolored, and sometimes tender to the touch. AKs grow slowly and are usually benign (non-cancerous).


Look for areas of your skin that become scaly, rough, discolored, and sometimes tender to the touch.

AKs are most commonly found on sun-exposed areas such as the face, lips, ears, neck, scalp, forearms, and backs of hands.

Learn how to examine your skin

Risk factors of actinic keratosis

Chronic exposure to sunlight alters the cells that make up the majority of the epidermis, which can lead to AKs. People who have fair skin and light-colored hair and eyes are at greatest risk.

Individuals who are immunosuppressed, either by cancer chemotherapy treatments or organ transplants, or who have an immunodeficiency disorder, are also considered high risk.

Potential consequences

AKs are not life-threatening as long as they are diagnosed and treated in the early stages. Left untreated, aggressive AKs may progress into squamous cell carcinoma, a serious type of skin cancer.
Those with multiple AKs have a 10% higher risk of squamous cell carcinoma.
Source: American Cancer Society, 2020

Testing and diagnosing actinic keratosis

Doctors often diagnose and treat AKs based on clinical appearance alone though sometimes a skin biopsy is needed. If a dermatologist assesses your skin tissue and determines the lesion is an AK, they will discuss several treatment options with you and help you decide which is best.

Treatment options for actinic keratosis

Common treatment options for actinic keratosis include:

  • Freezing lesions with liquid nitrogen (cryosurgery)
  • Topical chemotherapy creams
  • Photodynamic therapy
  • Chemical peels
  • Laser resurfacing therapy
Your treatment may vary based on the number of AKs you have developed, their location, and size. Your age and general health will also be taken into consideration.

Preventing actinic keratosis

To protect yourself from actinic keratosis, the most important prevention measure you can take is to avoid overexposure to sunlight.

You should also inspect your entire body regularly for any skin changes, and routinely visit your physician for a skin examination.

Learn more about recommended prevention and protection techniques from Spot the Spot.

Get protection tips

Actinic keratosis resources


Review information on actinic keratosis or other skin disorders with your dermatologist. Download or print these brochures and bring them to your next appointment.

Open AK brochure Open skin disorders brochure
58 million Americans have one or more AKs.
Source: Skin Cancer Foundation

Other types of skin cancer

  • Also known as atypical moles, these benign lesions look different than common moles.
  • This is the most common form of skin cancer and usually occurs on sun-exposed areas of the body.
  • This serious form of skin cancer affects the cells that produce melanin.
  • This major cancer arises from the outer layer of the skin and mucous membranes.
  • This common, non-cancerous lesion grows on the outer layer of the skin.