Actinic keratosis, also called solar keratosis, is a precancerous skin lesion. Untreated, actinic keratosis can develop into squamous cell carcinoma. In fact, according to the Skin Cancer Foundation, 40 to 60 percent of squamous cell carcinomas develop from actinic keratosis lesions, and 10 percent of all actinic keratosis lesions eventually become cancerous (2010). Early treatment of these lesions is important for preventing squamous cell carcinoma.
Actinic Keratosis Causes and Risk Factors
Long-term, unprotected sun exposure is the top risk factor for actinic keratosis. UV exposure from indoor tanning beds or sun lamps can also cause actinic keratosis. UV rays damage cells in the skin’s top layer, called the epidermis. In some cases, exposure to x-rays or chemicals can increase the risk for developing actinic keratosis.
Individuals such as construction workers or farmers who spend long periods of time out in the sun are at higher risk for developing actinic keratosis. This is particularly true for those who do not use sunscreen or protective clothing.
Actinic keratosis can affect people at any age, but those most susceptible include individuals with fair skin, blue or green eyes and red or blonde hair and older people who have accumulated years of sun damage.
Symptoms of Actinic Keratosis
Actinic keratoses most often develop on skin that has had frequent, long-term exposure to sunlight. Commonly affected areas include the face, arms and back. Actinic keratosis lesions are slow to develop and may be very small at first. They may be more easily detected by touching the skin, as they cannot always be seen. They rarely appear just one lesion at a time.
Actinic keratosis lesions can itch, burn or cause discomfort. They are usually:
- Flat or slightly raised
- From one eighth inch to one inch in diameter
- Red, tan, pink or flesh-colored
- Scaly or rough.
Actinic keratoses may closely resemble squamous cell carcinoma lesions.
Actinic Keratosis Treatment
Removal is almost always advised for actinic keratoses because of the associated cancer risk. Early actinic keratosis treatment is important to prevent the lesion from developing into squamous cell carcinoma. Several treatment options are available, such as:
- Chemical peeling, which destroys the actinic keratosis and promotes the growth of new cells
- Cryotherapy, which involves freezing the lesions with liquid nitrogen
- Curettage or dermabrasion, in which specialized instruments are used to scrape off affected cells
- Laser therapy, which uses a laser to remove actinic keratosis cells
- Topical creams, which destroy the abnormal cells.
Treatment choices depend on the size, location and characteristics of the lesion. Your doctor will recommend the best method for your case.
Mayo Clinic. (2009). Actinic keratosis. Retrieved June 24, 2010, from http://www.mayoclinic.com/health/actinic-keratosis/DS00568
Medline Plus. (2009). Actinic keratosis. Retrieved June 24, 2010, from http://www.nlm.nih.gov/medlineplus/ency/article/000827.htm
The Skin Cancer Foundation. (2010). Actinic keratosis: the most common precancer. Retrieved June 24, 2010, from http://www.skincancer.org/actinic-keratosis-and-other-precancers.html