July 17, 2018
Actinic Keratosis: Sun Damage

Actinic Keratosis: Sun Damage

by Berkeley Wellness

If you’ve spent a lot of time in the sun over the years—and especially if you’re fair-skinned, freckly and burn easily— there’s a good chance you’ll develop skin lesions called actinic or solar keratoses (plural of keratosis) as you get older. These are small, rough, scaly or just flaky patches, typically found on areas most exposed to the sun. They may be slightly pink, but also red, brown or beige, and they may be flat or raised. Sometimes they itch and burn. As many as 26 percent of all adults in the U.S.—and more than 60 percent of those over age 60—have at least one actinic keratosis, making it the most common skin condition after acne.

How risky are actinic keratoses?

Most actinic keratoses remain stable or even go away—especially if you limit sun exposure. But some progress to squamous cell skin cancer (not basal cell cancer or the more dangerous melanoma)—by some estimates, less than 1 percent become cancerous in the first year, but the rate increases over the years. The risk seems to be greater if the lesion is larger than one centimeter (0.4 inches), grows quickly, bleeds, is red or hard, or has become ulcerated—or if you have multiple lesions. There may be genetic factors as well. Where on the spectrum actinic keratoses fall—from simply sun-damaged skin to early cancers is debatable— but there’s general agreement that all should be treated.

An actinic keratoses action plan

There are several ways to treat actinic keratoses. Which is best depends on the size and number of lesions, where they are and your history of skin cancer, as well as aesthetic, time and cost issues. Your doctor may have a preferred method, but it’s good to know your options so you can have a say in the matter. Keep in mind that none are 100 percent effective and recurrences are always possible, plus all carry some risk of scarring and other skin changes. Insurance may not cover all of them.

In general, surgical procedures are best if you have a single or just a few lesions. Topical medications can treat multiple lesions (including undetectable ones), but they can be more expensive, require repeated applications over time at home and often cause prolonged inflammation and irritation.

At the doctor’s office

  • Cryosurgery. This uses liquid nitrogen to freeze and destroy lesions. It hurts but is over quickly. It leaves a red sore that may blister and peel and can take a few weeks to fully heal.
  • Excision or curettage. If the lesion looks suspicious or is particularly thick, your doctor may cut or scrape it away after giving a local anesthetic. The tissue can then be evaluated for cancer.
  • Photodynamic therapy. A chemical is applied to the skin to make it sensitive to a particular wavelength of light. The lesion is then destroyed when exposed to a special light. It takes more than an hour, you have to avoid exposure of the spot to ultraviolet light for 48 hours after, and you can have redness, swelling, peeling and blistering that can take one to two weeks to heal.
  • Chemical peels. Various chemicals are used to peel away damaged skin so new healthy skin can grow. This can be effective but is not likely to be covered by insurance because it’s considered cosmetic. Other “cosmetic” procedures sometimes used for actinic keratoses include laser resurfacing and dermabrasion.

At-home topical medications

  • 5-fluorouracil (5-FU). This chemotherapy drug, applied as a cream or solution, causes death of abnormal cells. It is generally used twice a day for two to three weeks.
  • Imiquimod. Originally used for genital warts, this cream stimulates your immune system to attack the damaged skin. It’s used two to three times a week for several months.
  • Diclofenac. This nonsteroidal antiinflammatory gel is used twice a day for three months. It produces only mild to moderate local skin reactions, but users must especially avoid sunlight. Some doctors prescribe it only for patients who don’t respond enough to 5-FU.
  • Ingenol mebutate. Approved by the Food and Drug Administration (FDA) in 2012, this new and very expensive drug works through both cell destruction and by affecting the immune system. It appears to be as effective as other topical medications but requires only once-daily application for two or three days and causes skin irritation that resolves relatively quickly. In a large study in the New England Journal of Medicine, 98 percent of participants completed the treatment with no serious side effects and only minimal scarring or skin discoloration.
  • Bottom line: If you notice a scaly lesion that doesn’t clear up, see a dermatologist. There’s no single best way to treat actinic keratoses, and sometimes several treatments are used. You should discuss the pros and cons of each with your doctor. But your best defense against them is to protect your skin, especially in sunnier months: Wear a hat, long-sleeved shirt, and other protective clothing; use sunscreen with an SPF of at least 15; limit or avoid sun exposure between 10 a.m. and 4 p.m. and avoid tanning salons and sunlamps. These measures not only help prevent actinic keratoses, they also reduce the chance that the lesions will progress or recur—and may even help them resolve on their own.

    Actinic Keratosis: A Diet Link?

    Research on the relationship between what you eat and actinic keratoses is very limited, but one study linked a certain kind of food—and a drink—to a reduced risk of these skin lesions.