Diseases & Conditions

Actinic keratosis

An actinic keratosis is a skin lesion that appears as a rough, scaly patch on your face, lips, ears, back of your hands, forearms, scalp and neck. The cause is frequent or intense exposure to ultraviolet (UV) rays, typically from the sun.

An actinic keratosis, also known as solar keratosis, enlarges slowly and usually causes no signs or symptoms other than a patch or small spot on your skin. An actinic keratosis takes years to develop, usually first appearing in older adults. Many doctors consider an actinic keratosis to be precancerous because it can develop into skin cancer.

You can reduce your risk of actinic keratosis by minimizing your sun exposure and protecting your skin from UV rays.

Frequent or intense exposure to ultraviolet (UV) rays, typically from the sun, causes an actinic keratosis.

An actinic keratosis begins in your skin's top layer — the epidermis. The epidermis is as thin as a pencil line, and it provides a protective layer of skin cells that your body continually sheds.

Normally, skin cells within the epidermis develop in a controlled and orderly way. In general, healthy new cells push older cells toward the skin's surface, where they die and eventually are sloughed off. When skin cells are damaged through UV radiation, changes occur in the skin's texture and color, causing blotchiness and bumps or lesions.

Most of the damage to skin cells results from exposure to UV radiation from sunlight and commercial tanning lamps and beds. The damage is cumulative, so the more time you spend in the sun or in a tanning booth, the greater your chance of developing skin cancer. Your risk increases even more if most of your outdoor exposure occurs at times of the day or in locations where the sunlight is most intense.

Your doctor can usually diagnose actinic keratoses by inspecting the skin. If there's any doubt, your doctor may do other tests, such as a skin biopsy. During a skin biopsy, your doctor takes a small sample of your skin (biopsy) for analysis in a lab. A biopsy can usually be done in a doctor's office using a local anesthetic.

If treated early, almost all actinic keratoses can be eliminated before developing into skin cancer. However, if left untreated these spots or patches may progress to squamous cell carcinoma, a serious form of skin cancer.

An actinic keratosis may be the earliest form of squamous cell carcinoma. This type of cancer usually isn't life-threatening if detected and treated early. However, actinic keratoses can grow to be large and invade surrounding tissues, some spreading (metastasizing) to other parts of your body.

It's impossible to tell exactly which patches or lesions will develop into skin cancer. Therefore, actinic keratoses are usually removed as a precaution. Your doctor can discuss with you which treatment is appropriate for you.

Actinic keratosis treatment options may include:

• Freezing (cryotherapy). An extremely cold substance, such as liquid nitrogen, is applied to skin lesions. The substance freezes the skin surface, causing blistering or peeling. As your skin heals, the lesions slough off, allowing new skin to appear. This is the most common treatment, takes only a few minutes, and can be performed in your doctor's office.
• Creams or ointments. Some topical medications contain fluorouracil, a chemotherapy drug. The medication destroys actinic keratosis cells by blocking essential cellular functions within them. Another treatment option is imiquimod (Aldara), a topical cream that modifies the skin's immune system to stimulate your body's own rejection of precancerous cells.
• Chemical peeling. This involves applying one or more chemical solutions — trichloroacetic acid (TCA), for example — to the lesions. The chemicals cause your skin to blister and eventually peel, allowing new skin to form. This procedure may not be covered by insurance, because it's considered cosmetic.
• Scraping (curettage). In this procedure, your surgeon uses a device called a curet to scrape off damaged cells. Scraping may be followed by electrosurgery, in which a pencil-shaped instrument is used to cut and destroy the affected tissue with an electric current.
• Photodynamic therapy. With this procedure, an agent that makes your damaged skin cells sensitive to light (photosensitizing agent) is either injected or applied topically. Your skin is then exposed to intense laser light to destroy the damaged skin cells.
• Laser therapy. A special laser is used to precisely remove the actinic keratoses and the affected skin underneath. Local anesthesia is often used to make the procedure more comfortable. Some pigment loss and scarring may result from laser therapy.
• Dermabrasion. In this procedure, the affected skin is removed using a rapidly moving brush. Local anesthetic is used to make the procedure more tolerable.

Talk to your doctor about your treatment options. The procedures have various advantages and disadvantages, including side effects, risk of scarring, and the number of treatment sessions required. Actinic keratoses are usually very responsive to treatment. Afterward you'll likely have regular follow-up visits to check for new patches or lesions.