Actinic Keratoses
Actinic keratoses (AKs) are dry, scaly, rough-textured patches or lesions that form on the outermost layer of the skin after years of exposure to ultraviolet (UV) light, such as sunlight. These lesions typically range in color from skin-toned to reddish brown, and in size from that of a pinhead to larger than a quarter. Occasionally, a lesion grows to resemble an animal horn and is called a “cutaneous horn.”
It is important that anyone with AKs be seen by a dermatologist. AKs are considered the earliest stage in the development of skin cancer and have the potential to progress to squamous cell carcinoma, a type of skin cancer that can be fatal. Anyone who develops AKs has extensively sun-damaged skin. This makes them more susceptible to other forms of skin cancer, including melanoma. Melanoma is considered the most lethal form of skin cancer because it can rapidly spread to the lymph system and internal organs.
Why the Term “Actinic Keratoses”
The two words “actinic” and “keratoses” precisely describe what has happened to the skin. “Actinic” (ak-‘ti-nik) comes from the Greek word for ray, “aktis,” and indicates that radiant energy has produced chemical changes. The word “keratoses” (ker-ah-TOE-sees) means the skin has become hard and callous. Therefore, AKs are areas of calloused skin caused by chemical changes brought about by exposure to radiant energy, such as sunlight. The lesions may also be called “solar keratoses.”
When such a lesion occurs on the lip, dermatologists call the condition “actinic cheilitis” (key-LITE-iss). “Cheilitis” means inflammation of the lips. Actinic cheilitis is characterized by a diffuse scaling on the lower lip that cracks and dries. Sometimes the lip has a whitish discoloration on the thickened lip.
Causes
Years of sun exposure cause AKs to develop. All AKs, including actinic cheilitis, develop in the skin cells called the “keratinocytes,” which are the tough-walled cells that make up 90% of the epidermis, the outermost layer of skin, and give the skin its texture. Years of sun exposure cause these cells to change in size, shape, and the way they are organized. Cellular damage can even extend to the dermis, the layer of skin beneath the epidermis.
Who Gets Actinic Keratoses?
Individuals with fair skin, a history of cumulative sun exposure, or a weak immune system are at greatest risk for developing AKs. These lesions develop on areas of the body that have received years of sun exposure, such as the face, ears, lip, scalp, neck, forearms, and back of the hands. AKs usually appear after age 40 because they take a long time to develop. However, even teens can have AKs when they live in areas that receive high-intensity sunlight year round, such as Florida, Arizona and Southern California.
Research shows that p53, a mutant protein found in sun-damaged cells in the body, is present in more than 90% of people who have AKs and squamous cell carcinomas.
More Americans Developing AKs
Millions of Americans have AKs, and the number continues to grow. In fact, AKs are so common today that treatment for these lesions ranks as one of the most frequent reasons people consult dermatologists.
A survey conducted by the American Academy of Dermatology (AAD) confirmed what dermatologists have long suspected: The public’s behavior regarding sun protection has not improved significantly over the last two decades. Findings indicate that people are spending more time outdoors, not adequately protecting themselves from the sun, and still believe the appearance of a tan is healthy. The survey also found that younger people tend not to use sunscreen on a regular basis and are more likely to visit a tanning salon today than in the past.
Prevention and Early Detection Key
To prevent AKs and skin cancer, the AAD recommends adopting a comprehensive sun protection program that includes:
- Avoiding deliberate tanning. Ultraviolet light from the sun and tanning beds causes skin cancer and wrinkling. If you want to look like you’ve been in the sun, consider using a sunless self-tanning product. When using a self-tanning product, you should continue to use sunscreen.
- Getting vitamin D safely through a healthy diet that includes vitamin supplements. Don’t seek the sun.
- Generously applying sunscreen to all exposed skin. Before going outdoors, generously apply a sunscreen that has a Sun Protection Factor (SPF) of at least 30 and is broad-spectrum — protects against both ultraviolet (UVA) and ultraviolet B (UVB) rays. While outdoors, re-apply the sunscreen approximately every two hours, even on cloudy days, and after swimming or perspiring.
- Covering up when you must be in the sun. Wear long sleeves, pants, a wide-brimmed hat, and sunglasses that protect against both UVA and UVB rays.
- Using extra caution near water, snow, and sand. These reflect the damaging rays of the sun, which can increase your chance of sunburn.
When caught in the early stages, AKs and all types of skin cancer are treatable and, in most cases, curable. The key to early detection is frequent skin examinations. Performing regular self-examinations and being screened by a dermatologist as needed can help detect AKs and skin cancer in their earliest and most treatable stages.
If you find a suspicious skin lesion, be sure to see a dermatologist for diagnosis — even if the lesion seems to disappear for weeks or months before reappearing. Dermatologists receive extensive medical training in skin conditions and have the experience necessary to diagnose various skin lesions. An accurate diagnosis is the first step to successful treatment.
Self-treating by picking off the lesions is not effective treatment; the lesions grow back. Since AKs have the potential to progress to squamous cell carcinoma, a sometimes fatal type of skin cancer, all AKs should be professionally treated.
What Actinic Keratoses are Not
While the terminology that dermatologists use can seem confusing, the precise terms allow dermatologists to clearly differentiate skin conditions and prescribe appropriate treatment. Described below are some skin conditions that patients may confuse with AKs. The following conditions are not AKs:
Actinic porokeratosis: Similar in appearance to AKs, this is an uncommon, usually inherited, skin condition characterized by sun sensitivity that causes reddish brown scaly spots to develop, primarily on the arms and legs. The lesions appear after years of sun damage to the skin, so they are typically seen in middle-aged and older individuals. The lesions tend to grow or itch after sun exposure and are fairly resistant to treatment.
Seborrheic dermatitis: This is a red, scaly rash that itches. Seborrhea is excessive oiliness of the skin, especially on the scalp and face, without redness or scaling. If seborrhea progresses to seborrheic dermatitis, redness and scaling appear.
Seborrheic keratoses: Also called “benign keratoses,” these non-cancerous growths have a waxy, pasted-on look and develop on the outer layer of skin. Lesions range in size from a fraction of an inch in diameter to larger than a half dollar. AKs are flatter, redder, and rougher to the touch than seborrheic keratoses.
Treatments
Actinic keratoses (AKs) are so common today that treatment for these lesions ranks as one of the most frequent reasons that people consult a dermatologist.
Often patients want these lesions removed for cosmetic purposes, since AKs tend to occur in highly visible places such as the hands, arms, face, and neck. Whether or not cosmetic concerns are a motivating factor, it is extremely important to consult a dermatologist or dermatologic surgeon when an actinic keratosis (AK) lesion is suspected. Left untreated, AKs have the potential to progress to squamous cell carcinoma, a form of skin cancer that can be life threatening.
Diagnosis
AKs have unique physical characteristics that allow dermatologists to visually identify these lesions. However, if an AK is especially large or thick, the lesion may be surgically removed for microscopic examination (biopsy) to determine if squamous cell carcinoma is present.
When an AK is diagnosed, dermatologists consider a number of factors before choosing the most appropriate treatment method. Factors include:
- Size, number, location, and stage of the lesions
- Age, health, and medical history of the patient
- Occupation
- Cosmetic expectations and treatment preferences
- Patient compliance (i.e., willingness to self-treat as needed for several weeks)
- History of previous treatment
How AKs are Treated
There are several treatment options for AKs, including cryosurgery (freezing), surgical excision, curettage (scraping) with or without electrosurgery (heat generated by an electric current) and topical (applied to the skin) medications. Lasers, chemical peels, dermabrasion, and photodynamic therapy may also be used.
Patients who have multiple AKs may not have all lesions treated at the same time, and in some cases, the dermatologist or dermatologic surgeon will use more than one treatment option.
What to Expect After Treatment
Practice Sun Safety. Sun safety practices are a medical necessity in order to prevent new AKs and squamous cell carcinoma from developing. After treatment, patients routinely receive guidelines for practicing sun safety.
Sun safety practices include:
- Avoiding excessive exposure to sunlight. Stay out of direct sun exposure during peak (10a.m. — 4p.m.) sunlight hours.
- Using a broad-spectrum sunscreen with a SPF of 30 or higher. Broad-spectrum sunscreen provides protection from both the UVA and UVB rays of the sun. Apply broad-spectrum sunscreen at least 15 to 30 minutes before going outdoors, even on cloudy days.
- Reapplying sunscreen approximately every two hours. When outdoors and even on cloudy days, be sure to reapply sunscreen approximately every two hours.
- Wearing protective clothing. When outdoors during daylight, wear a wide-brimmed hat, sunglasses that block 100% of the UV rays and tightly knit clothing that covers arms and legs.
Topical Retinoids. In addition to sun-protection practices, topical (applied to the skin) retinoids (vitamin A derivatives) may be prescribed. Topical retinoids are not suitable for every patient, but may be prescribed in some cases to help prevent new AKs from developing.
Re-examination. Dermatologists and dermatologic surgeons regularly re-examine patients treated for AKs. Frequency depends on the extent of the AKs, sun-damaged skin, and the treatment method. Re-examination may be as frequent as every 8 to 12 weeks or require only 1 to 2 visits per year. It is extremely important to keep these re-examination appointments because when enough sun damage occurs to cause AKs, the possibility of developing more AKs or even skin cancer greatly increases.
Re-treatment. Re-treatment is sometimes necessary as new AKs can develop and occasionally AKs recur. Whenever a lesion is spotted, be sure to consult a dermatologist or dermatologic surgeon, because left untreated AKs have the potential to progress to squamous cell carcinoma.