Actinic keratosis also known as a solar keratosis, is a rough, scaly patch on your skin that develops from years of exposure to the sun. It's most commonly found on your face, lips, ears, back of your hands, forearms, scalp or neck.
While an actinic keratosis is not a skin cancer, it is considered to be precancerous. If left untreated, it can develop into squamous cell carcinoma.
It enlarges slowly and usually causes no signs or symptoms other than a patch or small spot on your skin. These patches take years to develop, usually first appearing in people over 40.
A small percentage of actinic keratosis lesions can eventually become skin cancer.
Causes and risk factors of actinic keratosis
AK is primarily caused by long-term exposure to sunlight. You have a higher risk of developing this condition if you:
Are older than 60
Live in a sunny climate
Have a history of frequent or intense sun exposure or sunburn
Have red or blond hair, and blue or eyes
Tend to freckle or burn when exposed to sunlight
Have a personal history of an actinic keratosis or skin cancer
Have a weak immune system as a result of chemotherapy, , AIDS or organ transplant medications
have skin and blue eyes
have a tendency to sunburn easily
have a history of sunburns earlier in life
have human papilloma virus (HPV)
Symptoms of actinic keratosis
Actinic keratoses start out as thick, scaly, crusty skin patches. These patches are usually about the size of a small pencil eraser. There might be itching or burning in the affected area.
Over time, the lesions can disappear, enlarge, remain the same, or develop into SCC. There’s no way of knowing which lesions may become cancerous.
Rough, dry or scaly patch of skin, usually less than 1 inch (2.5 ) in diameter
Flat to slightly raised patch or bump on the top layer of skin
In some cases, a hard, surface
as varied as pink, red or brown
Itching or burning in the affected area
Actinic keratoses are found primarily on areas exposed to the sun, such as your face, lips, ears, hands, forearms, scalp and neck.
If treated early, almost all actinic keratoses can be cleared up or removed before they develop into skin cancer. If left untreated, some of these spots may progress to squamous cell carcinoma — a type of cancer that usually isn't life-threatening if detected and treated early.
Protect your skin from the sun. Studies have shown that regular use of sunscreen – even on cloudy days – can help prevent actinic keratoses from forming.
Avoid using tanning beds or other indoor tanning devices; the lamps used in such equipment emit ultraviolet radiation that can be stronger than the sun’s rays.
Other sun safety precautions include: seeking shade, wearing a wide-brimmed hat, sunglasses and sun-protective clothing. Patients with evidence of photodamage or a history of actinic keratosis should be regularly monitored for new lesions.
Check your skin regularly and report changes to your doctor. Examine your skin regularly, looking for the development of new skin growths or changes in existing moles, freckles, bumps and birthmarks. With the help of mirrors, check your face, neck, ears and scalp. Examine the tops and undersides of your arms and hands.
Your doctor may be able to diagnose simply by looking at it.
During a skin biopsy, your doctor takes a small sample of your skin for analysis in a lab. A biopsy can usually be done in a doctor's office after a numbing injection.
An actinic keratosis sometimes disappears on its own, but it typically returns after more sun exposure. Because it's impossible to tell which patches or lesions will develop into skin cancer, actinic keratoses are usually removed as a precaution.
If you have several actinic keratoses, you may be better served by treating the entire affected area. Prescription products that can be applied to your skin for this purpose include:
Fluorouracil cream (, , )
Imiquimod cream (, )
Diclofenac gel (, )
These creams may cause redness, scaling or a burning sensation for a few weeks.
Surgical and other procedures
Treatments include cryosurgery where doctor freezes the lesion with liquid nitrogen and various creams that destroy precancerous cells. Occasionally, surgery is required as treatment or to sample a lesion to ensure that it has not progressed to a skin cancer.
Although individual actinic keratosis can be effectively treated with liquid nitrogen, your physician may suggest something called “field therapy”. This entails applying a medicated cream to an entire area ( the entire nose, forehead or cheeks) for a designated period of time. This not only treats visible actinic keratoses, but also surrounding actinic keratoses that may not be visible to the naked eye. We call these “subclinical” actinic keratoses.
Field therapy can be accomplished with other modalities, including light-based treatments such as photodynamic therapy.
Your dermatologist will advise on the most suitable treatment based on the number of lesions, their location, your age and general health.