You have surely seen an actinic keratosis. The name may be unfamiliar, but the appearance is commonplace. Anyone who spends time in the sun runs a high risk of developing one or more.
An actinic keratosis, also known as a solar keratosis, is a scaly or crusty bump that arises on the skin surface. The base may be light or dark, tan, pink, red, or a combination of these or even the same color as your skin. The scale or crust is dry and rough. Occasionally it itches or produces a pricking or tender sensation. The skin lesion develops slowly and usually reaches a size from an eighth to a quarter of an inch.
A keratosis is most likely to appear on the face, ears, bald scalp, neck, backs of hands and forearms, and lips. It tends to lie flat against the skin of the head and neck and be elevated on arms and hands.
Actinic Keratosis is Dangerous
Actinic Keratosis can be the first step in the development of skin cancer. Therefore it is referred to as a precursor of cancer or a precancer. It is estimated that up to 10 percent of active lesions, which are redder and more tender than the rest, will take the next step and progress to squamous cell carcinomas. They are usually not life threatening, provided they are detected and treated in the early stages. However, left untreated, they can grow large and invade the surrounding tissue. On rare occasions, they metastasize or spread to the internal organs.
The most aggressive form of keratosis, actinic cheilitis, appears on the lips and can evolve into squamous cell carcinoma. When this happens, roughly one-fifth of these carcinomas metastasize. The presence of actinic keratoses indicates that sun damage has occurred and that any kind of skin cancer—not just squamous cell carcinoma—can develop.
What Does Actinic Keratosis Look Like?
The look of actinic keratosis varies depending on where it's found on the body:
Back of hand—scattered, thickened red, scaly patches.
Sun-damaged forehead or bald scalp—small red bumps and/or small tan crusts.
Lower lip—fissures filled with dried blood and large keratosis covered with thorny scale.
Cheek and ear-crusted lesions—ranging in color from red to brown.
If you spot any of these, consult your doctor promptly.
Causes of Actinic Keratosis
Sun exposure is the cause of almost all actinic keratoses. Sun damage to the skin accumulates over time, so that even a brief exposure adds to the lifetime total. The likelihood of developing keratoses is highest in regions close to the equator. However, regardless of climate, everyone is exposed to the sun. Ultraviolet rays reflect off sand, snow, and other surfaces; about 80 percent can pass through clouds.
Are You at Risk?
People who have fair skin, blonde or red hair, blue, green, or gray eyes are at the greatest risk. Because their skin has less protective pigment, they are the most susceptible to sunburn. Even those who are darker-skinned can develop keratoses if they expose themselves to the sun without protection. African-Americans, however, rarely have these lesions.
Individuals, who are immunosuppressed as a result of cancer, chemotherapy, AIDS, or organ transplantation, are also at higher risk.
How Common is It?
One in six people will develop an actinic keratosis in the course of a lifetime, according to the best estimates. Older people are more likely than younger ones to have actinic keratoses, because cumulative sun exposure increases with the years.
A survey of older Americans found keratoses in more than half of the men and more than a third of the women aged 65 to 74 who had a high degree of lifetime sun exposure. Some experts believe the majority of people who live to the age of 80 have keratoses. Because more than half of an average person's lifetime sun exposure occurs before the age of 20, keratoses appear even in people in their early twenties who have spent too much time in the sun with little or no protection.
How Can You Prevent It?
The best way to prevent actinic keratosis is to protect yourself from the sun.
Limit the amount of time spent in the sun.
Avoid the peak hours from 10 a. m. to 4 p.m.
Cover up with protective clothing, including a broad-brimmed hat.
Wear a broad-spectrum sunscreen with a sun protection factor (SPF) of 30 or greater.
Avoid tanning parlors and artificial tanning devices.
Keep newborns out of the sun. Sunscreens can be used on babies over the age of six months.
Teach your children good sun-protection practices.
Perform regular skin self-examination and consult a dermatologist if you find a suspicious area.
How is It Treated?
There are a number of effective treatments for actinic keratosis. The right treatment for you will depend on the size and site and aggressiveness of the lesion, as well as the health and wishes of the patient. Your dermatologist can help you choose among the following possible treatments:
Cryosurgery– This is the most commonly used procedure. It involves freezing off the lesions through application of liquid nitrogen with a special spray device. It does not require anesthesia and produces no bleeding. There is a slight risk of scaring and hypopigmentation.
Topical Medications – Multiple topical medications can be used at home to treat these lesions, especially when the lesions are large or numerous. Those medications include fluorouracil®, imiquimod®, Picato®, Soloraze®.
Actinic keratosis is the warning signal for skin cancer. Heed that signal. If you believe you may have actinic keratosis anywhere on your face, body, or scalp, make an appointment with your dermatologist today.