Actinic Keratosis: Get the Facts About this Common Pre-Cancer

**By Eric Brumwell, MD**

The name may be unfamiliar, but the appearance is common.

apply-sunscreenAlthough you may not have heard of actinic keratosis, if you’re someone who spends time in the sun, you run a high risk of developing one or more in your lifetime. In fact, since people often have more than one, it is common for dermatologists to refer to them in the plural, “keratoses.”

According to the Society for Investigative Dermatology and The American Academy of Dermatology, actinic keratosis is the most common pre-cancer in the United States. It affects more than 58 million Americans.

What are they? And what do they look like?

Actinic keratosis, also known as a solar keratosis, is a scaly or crusty bump that forms on the skin surface and may look like warts. Interestingly, it tends to lie flat against skin on the head and neck and be elevated on arms and hands.

As with other skin conditions, there are some tell-tale signs of actinic keratosis, including:

  • The base may be the same color as your skin. It might also be light, dark, tan, brown, pink, red or a combination
  • The crust is dry and rough or scaly
  • It can be tender, itch or cause a pricking sensation
  • They can also become inflamed and surrounded by redness
  • In rare cases, they can even bleed


An actinic keratosis is most likely to appear on parts of the body that have received more exposure to real or artificial sunlight – mainly through the use of tanning beds – and through the damaging effects of ultraviolet (UV) radiation. In rare cases, extensive exposure to X-rays can also cause them.

Where do they form?

The most common locations on the body where keratoses form include:

  • Face
  • Lips
  • Ears
  • Scalp
  • Neck
  • Backs of hands and forearms

They can also appear on shins and other parts of the legs.

Risk factors

Anyone can develop actinic keratosis, but you may be more likely to develop the condition if you:

  • Are 40 or older
  • Live in a sunny location
  • 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 actinic keratosis or skin cancer
  • Have a weak immune system from chemotherapy, leukemia, AIDS or organ transplant medications

Development and diagnosis

Actinic keratoses take years to develop. These skin lesions develop slowly and usually range from an eighth to a quarter of an inch in size.

In the beginning, an actinic keratosis is often so small that it is recognized by touch rather than sight. It feels like you are running a finger over sandpaper. Many times, patients may have more invisible – or “subclinical” – lesions than those that are visible on the surface of the skin.

A dermatologist will likely be able to determine whether you have an actinic keratosis simply by examining your skin. If there is any doubt, he or she may do other tests, such as a skin biopsy.


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

If you have several actinic keratoses, dermatologists often recommend treating the entire affected area.

Treatment options include:

  • Various prescription creams
  • Photodynamic therapy – chemical solution is applied to a keratosis to make it sensitive to light. The affected area is then exposed to artificial light to destroy the damaged skin cells
  • If you have only a few actinic keratoses, your doctor may recommend removing them by freezing (cryotherapy) or scraping (curettage)

The good news

If treated early, almost all actinic keratoses can be cleared up or removed before they develop into skin cancer.

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.

If not treated

Actinic keratosis is considered a pre-cancer because, if left alone, it could develop into a skin cancer – most often the second most common form of the disease, squamous cell carcinoma. According to the American Cancer Society, more than 1 million cases of squamous cell carcinoma are diagnosed in the United States each year.


People can reduce their risk of actinic keratoses by simply minimizing exposure to sunlight and protecting skin from UV rays. The best approach to do that is to cover your body when in the sun. Clothes with built-in UV protection are helpful, but so is covering exposed skin with sunscreen containing a higher Sun Protection Factor (SPF) rating.

Dermatologists recommend using a sunscreen with an SPF of at least 30, which blocks 97 percent of the sun’s harmful UV rays. Higher-number SPFs block a bit more, but no sunscreen can block 100 percent of the sun’s rays.

I will leave you with a quote from a fellow physician, Howard Murad, MD. Its beauty is in its simplicity: “Healthy skin is a reflection of overall wellness.”

Eric Brumwell, MD, is a board certified dermatologist with special interests in skin cancer prevention and treatment. He practices at Virginia Mason Bainbridge Island Medical Center.

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