Actinic Keratosis

Actinic Keratosis

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 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.

Why is it 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?

If you spot any of these, consult your doctor promptly.

What is the cause?

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.

Who is at greatest 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 is it treated?

There are a number of effective treatments for actinic keratoses. Not all keratoses need to be removed. The decision on whether and how to treat is based on the nature of the lesion, your age, and your health.

Curettage and Electrodessication—is the most commonly used treatment. The physician scrapes the lesion and takes a biopsy to test for malignancy. Bleeding is controlled by electrocautery-heat produced by an electric needle.

Shave Removal—utilizes a scalpel to shave the keratosis and obtain a specimen for testing. The base of the lesion is destroyed, and the bleeding is stopped by cauterization.

Cryosurgery—freezes off the lesions through application of liquid nitrogen with a special spray device or cotton-tipped applicator. It does not require anesthesia and produces no bleeding, but white spots sometimes result.

Dermabrasion—removes the upper layers of the skin by sanding or using a fine wire brush operating at 20-25,000 revolutions per minute. Redness and soreness usually disappear after a few days.

Topical Medications—two medicated creams are effective in removing keratoses, particularly when lesions are numerous. The medication is applied twice daily, with progress checked by a physician. 5-Fluorouracil (5-FU) cream is used for three to five weeks. Treatment leaves the affected area temporarily reddened and may cause some discomfort resulting from skin breakdown. Masoprocol cream, 10%, the newest topical treatment, is applied for 28 days. Redness and flaking are the most common side effects; most reactions are usually reported as mild to moderate.

How to prevent it

The best way to prevent actinic keratosis is to protect yourself from the sun.

Actinic keratosis is skin cancer's warning signal. Heed that signal.