An actinic keratosis (ak-TIN-ik ker-uh-TOE-sis) is a rough, scaly patch on your skin that develops from years of exposure to the sun. It’s most commonly found on your face, lips, ears, back of your hands, forearms, scalp or neck.

Also known as a solar keratosis, an actinic keratosis enlarges slowly and usually causes no signs or symptoms other than a patch or small spot on your skin. These patches take years to develop, usually first appearing in people over 40.

A small percentage of actinic keratosis lesions can eventually become skin cancer. You can reduce your risk of actinic keratoses by minimizing your sun exposure and protecting your skin from ultraviolet (UV) rays.

Symptoms

The signs and symptoms of an actinic keratosis include:

• Rough, dry or scaly patch of skin, usually less than 1 inch (2.5 centimeters) in diameter
• Flat to slightly raised patch or bump on the top layer of skin
• In some cases, a hard, wartlike surface
• Color as varied as pink, red or brown
• Itching or burning in the affected area

Actinic keratoses are found primarily on areas exposed to the sun, such as your face, lips, ears, hands, forearms, scalp and neck.

When to see a doctor

It can be difficult to distinguish between noncancerous spots and cancerous ones. So it’s best to have new skin changes evaluated by a doctor — especially if a spot or lesion persists, grows or bleeds.

Causes

An actinic keratosis is caused by frequent or intense exposure to UV rays, from the sun or from tanning beds.

Risk factors

Anyone can develop actinic keratoses. But you may be more likely to develop the condition if you:

• Are older than 40
• Live in a sunny climate
• Have a history of frequent or intense sun exposure or sunburn
• Have red or blond hair, and blue or light-colored eyes
• Tend to freckle or burn when exposed to sunlight
• Have a personal history of an actinic keratosis or skin cancer
• Have a weak immune system as a result of chemotherapy, leukemia, AIDS or organ transplant medications

Complications

If treated early, almost all actinic keratoses can be cleared up or removed before they develop into skin cancer. If left untreated, some of these spots may progress to squamous cell carcinoma — a type of cancer that usually isn’t life-threatening if detected and treated early.

Prevention

Prevention of actinic keratoses is important because the condition can precede cancer or be an early form of skin cancer. Sun safety is necessary to help prevent development and recurrence of actinic keratosis patches and spots.

Take these steps to protect your skin from the sun:

• Limit your time in the sun. Especially avoid time in the sun between 10 a.m. and 2 p.m. And avoid staying in the sun so long that you get a sunburn or a suntan. Both result in skin damage that can increase your risk of developing actinic keratoses and skin cancer. Sun exposure accumulated over time may also cause actinic keratoses.
• Use sunscreen. Daily use of sunscreen reduces the development of actinic keratoses. Before spending time outdoors, apply a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 15. The American Academy of Dermatology recommends using a broad-spectrum, water-resistant sunscreen with an SPF of at least 30.

  Use sunscreen on all exposed skin, and use lip balm with sunscreen on your lips. Apply sunscreen 15 minutes before sun exposure and reapply it every two hours or more often if you swim or sweat.

• Cover up. For extra protection from the sun, wear tightly woven clothing that covers your arms and legs. Also wear a broad-brimmed hat, which provides more protection than does a baseball cap or golf visor. You might also consider wearing clothing or outdoor gear specially designed to provide sun protection.
• Avoid tanning beds. The UV exposure from a tanning bed causes just as much skin damage as a tan acquired from the sun. And because the radiation of a tanning bed is absorbed in a short time, the photoaging process is accelerated and increases your risk of skin cancer.
• Check your skin regularly and report changes to your doctor. Examine your skin regularly, looking for the development of new skin growths or changes in existing moles, freckles, bumps and birthmarks. With the help of mirrors, check your face, neck, ears and scalp. Examine the tops and undersides of your arms and hands.
  

  Diagnosis

  Your doctor will likely be able to determine whether you have an actinic keratosis simply by examining your skin. If there’s any doubt, he or she may do other tests, such as a skin biopsy. During a skin biopsy, your doctor takes a small sample of your skin for analysis in a lab. A biopsy can usually be done in a doctor’s office after a numbing injection.

  Even after treatment for actinic keratosis, your doctor will likely suggest that you have your skin checked at least once a year for signs of skin cancer.

  Treatment

  An actinic keratosis sometimes disappears on its own, but it typically returns after more sun exposure. Because it’s impossible to tell which patches or lesions will develop into skin cancer, actinic keratoses are usually removed as a precaution.

  Medications

  If you have several actinic keratoses, you may be better served by treating the entire affected area. Prescription products that can be applied to your skin for this purpose include:

  • Fluorouracil cream (Carac, Fluoroplex, Efudex)
  • Imiquimod cream (Aldara, Zyclara)
  • Ingenol mebutate gel (Picato)
  • Diclofenac gel (Voltaren, Solaraze)

  These creams may cause redness, scaling or a burning sensation for a few weeks.

  Photodynamic therapy

  In photodynamic therapy, your doctor applies a chemical solution to the affected skin that makes it sensitive to light. He or she then exposes the area to artificial light to destroy the damaged skin cells. Side effects may include redness, swelling and a burning sensation during therapy.

  Surgical and other procedures

  If you have only a few actinic keratoses, your doctor may recommend removing them. The most common methods include:

  • Freezing (cryotherapy). Actinic keratoses can be removed by freezing them with liquid nitrogen. Your doctor applies the substance to the affected skin, which causes blistering or peeling. As your skin heals, the lesions slough off, allowing new skin to appear. Cryotherapy is the most common treatment. It takes only a few minutes and can be done in your doctor’s office. Side effects may include blisters, scarring, changes to skin texture, infection and darkening of the skin at the site of treatment.
  • 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 the doctor uses a pencil-shaped instrument to cut and destroy the affected tissue with an electric current. This procedure requires a local anesthetic. Side effects may include infection, scarring and changes in skin coloration at the site of treatment.