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. Research has shown that people with actinic keratoses have an increased risk of developing other types of skin cancer, including basal cell carcinoma and melanoma.

Guidelines published in 2015 for Canadian doctors recommend that all actinic keratoses be treated, since it is impossible to predict which ones will develop into skin cancer.

Actinic keratoses appear as red, rough scaling spots. These lesions appear on sun-exposed areas such as the face, ear, balding scalp, back of hand, forearm and leg. People usually have a few at a time, and the spots may sting or itch. Some actinic keratoses develop on the lower lip.

Fair-skinned people who freckle and burn easily are at greatest risk. People over 40 who have had considerable sun time also have a high risk for developing actinic keratoses. Outdoor workers face greater risk because of their extensive sun exposure.

Too much sun over many years leads to a disruption in the normal development of skin cells, affecting the upper skin layer called the epidermis. The sun’s rays damage the skin’s DNA, leading to this abnormal cell growth.

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.

Treatments include cryosurgery (freezing 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 (ie 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 (PDT).

Your dermatologist will advise on the most suitable treatment based on the number of lesions, their location, your age and general health.