Actinic keratosis (AK) is precancerous skin growths. It happens on sun-damaged areas.

Years of sunlight (UV) exposure damages skin. This causes it to grow abnormally. Patches on skin pale or redden causing a mottled appearance. Then rough, scaly, or crusted areas develop. These areas are usually pink, but can be gray. Sometimes a small horn of fingernail-like material grows. These lesions are more common in older men. This is probably related to occupational sun exposure.

The lesions are benign (noncancerous). They can occasionally convert to squamous cell skin cancer . This cancer must be surgically removed. AK changes to skin cancer in about 1 in 1000 cases. Patient that have many lesions have a higher chance of skin cancer.

AK may remain unchanged, spontaneously resolve, or progress to skin cancer. The fate of any one AK is impossible to predict. People with sun-damaged skin should see a doctor at regular intervals. The doctor will check for skin cancer .

Actinic Keratosis

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AKs develop because of high amounts of sun exposure.

Risk Factors

The following factors increase your chances of developing AK:

  • Fair complexion
  • Easy sunburning
  • Cumulative exposure to sun
  • Occupations or pastimes in sunlight (eg, farmer, lifeguard, outdoor sports)


If you have these lesions on your skin, do not assume they are actinic keratoses. These skin lesions may be cancer or another serious condition. If you find one of them, see your physician.

  • Mottled red and white, thinning skin on sun-exposed areas
  • Rough, scaly, or crusted patches on sun-exposed areas


Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be referred to a dermatologist. This is a doctor that focuses on skin issues.

A biopsy of the lesion may be done to look for cancer.


Talk with your doctor about the best plan for you. Treatment options include the following:

Surgical Removal

Individual lesions can be scraped or shaved with a scalpel. If there is a question of cancer, a biopsy specimen will be sent for examination.


Liquid nitrogen or a freeing spray kills the abnormal tissue. This will allow normal healing to replace the lesion.

5-fluorouracil (5-FU) Cream

The cream is applied twice a day for 2-4 weeks. 5-FU selectively attacks damaged skin so that normal skin can grow in its place. The result is temporary redness and rawness. The worse the reaction, the better the final result. This is the treatment of choice for badly damaged skin with multiple AKs.

Chemical Peeling

Various acids can destroy superficial layers of skin. This will allow normal skin to heal over the damage.

Photodynamic Therapy (PDT)

A chemical, 5-aminolevulinic acid, is applied to the skin. The chemical sensitizes the abnormal growths to light. If they are then exposed to strong light, the keratoses are destroyed.


This is a topical cream. It treats AK by creating a local immune response.

Diclofenac Gel

This is applied locally. It is found to be helpful in treating AK.


To help reduce your chances of getting AKs and skin cancer, take the following steps:

  • Avoid sun exposure.
  • Wear long sleeves, long pants or a long skirt, and a wide-brimmed hat when outdoors, especially during the middle of the day.
  • Use sun screen with an SPF of at least 15. Use of sunscreen was found to reduce the rate of actinic keratosis by 50%.