What It Is

While an actinic keratosis is not a skin cancer, it is 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.

Risk Factors

Fair-skinned people who freckle and burn easily are at greatest risk. People over 40 who have had considerable sun exposure are also at high risk for developing actinic keratoses. People who work outdoors or have hobbies with significant sun exposure (such as golfing, gardening and sailing) face greater risk because of their extensive sun exposure. In addition, people who have a weakened immune system (immunosuppressed) because of medications they take or from organ transplantation are at a higher risk for the development of actinic keratoses.


Actinic keratoses appear as red, rough scaly spots. These lesions appear on sun-exposed areas such as the face, ear, balding scalp, back of hands, forearms and legs. People usually have a few at a time, and the spots may sting or itch. Some actinic keratoses develop on the lower lip and look like a persistently rough patch.


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 treat pre-existing actinic keratoses and help prevent actinic keratoses from forming. It is recommended that you use sunscreen that is broad-spectrum with an SPF of 30+.  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: staying in the shade, wearing a wide-brimmed hat, sunglasses and sun-protective clothing as well as avoiding the sun from 10am to 4pm when the rays are the strongest. 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), that destroys 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 (i.e. the entire nose, forehead, cheeks and/or scalp) 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.