Definition

Actinic keratosis (AK) is abnormal growth of the skin. It results in a rough, scaly, or crusted patch of skin. AK tends to occur on sun-damaged skin.

AK is not cancer but it can sometimes change to squamous cell skin cancer. Treatment includes removing lesions and monitoring for skin cancer.

Causes

AK is caused by long term excessive sun exposure. Ultraviolet rays from sunlight can cause skin damage. Over time, this damage can cause abnormal growth of the skin, which may lead to AK or other disorders.

Risk Factors

Factors that may increase your chance of AK include:

• Fair skin color
• Easy sunburning
• Extra exposure to sun
• Occupations or pastimes in sunlight such as farmer, lifeguard, or athlete in outdoor sports

Symptoms

Symptoms may include:

• Spotted or smeared red, thinning skin
• Rough, scaly, or crusted patches

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

A biopsy of the lesion may be done. The skin will be closely examined for cancer.

Treatment

Talk with your doctor about the best treatment plan for you. AK lesions increase your risk of skin cancer. The lesions are usually removed to decrease this risk. The lesion will also be monitored for signs of cancer.

The exact method of removal will be determined by the number and location of the lesions.

AK may be removed with:

• Surgery
• Cryosurgery
• Chemical peel
• Photodynamic therapy

Medications may also be applied over the skin. More than one treatment may be required. Over time, the medication will remove the AK. Medication may be an option for people with multiple AKs.

The procedures and medications will remove AK and allow healthy skin to grow in its place. Most treatments have some risk of scarring or discoloration of the skin.

Prevention

To help reduce your chance of AK:

• Avoid sun exposure.
• Protect your skin when outdoors. Wear long sleeves, long pants or a long skirt. Use a wide-brimmed hat, especially during the middle of the day.
• Use sunscreen with an SPF of at least 30.

American Osteopathic College of Dermatology http://www.aocd.org

Canadian Dermatology Association http://www.dermatology.ca

Actinic keratosis. The Skin Cancer Foundation website. Available at:
http://www.skincancer.org/skin-cancer-information/actinic-keratosis
Accessed August 8, 2014.

Jeffes EW III, Tang, EH. Actinic keratosis. Current treatment options. Am J Clin Dermatol. 2000;1(3):167-179.

Rivers JK, Arlette J, Shear N, et al. Topical treatment of actinic keratoses with 3.0% diclofenac in 2.5% hyaluronan gel. Br J Dermatol. 2002;146(1):94-100.

Stockfleth E, Meyer T, Benninghoff B, Christophers E. Successful treatment of actinic keratosis with imiquimod cream 5%: a report of six cases. Br J Dermatol. 2001;144(5):1050-1053.

Sunscreen FAQs. American Academy of Dermatology website. Available at: https://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreen-faqs. Accessed October 20, 2014.