Actinic keratosis (AK) is a lesion that is widely considered to be precancerous growth on the skin. These lesions are typically small in size (3-6mm), flat, painless, and pink or colorless, and typically form on sun exposed skin. AKs often have a sandpaper like rough texture, and in its earlier stages, may be more noticeable by touch. Actinic keratosis that form on the lips are called actinic cheilitis (AC).
Some experts believe that they are actually the earliest form of a cancer called squamous cell carcinoma. In some sense this is a distinction without a difference from the point of view of patients.
At this time, there is no reliable way to predict which AK lesions will progress into squamous cell carcinoma, and therefore, AKs should be treated promptly either way.
The prevalence and incidence of actinic keratosis in Canada has not been specifically studied and therefore, data specific to Canadians are lacking. We can, however, reasonably make comparisons with a Northwest England study where 15% of men and 6% of women over the age of 40 had at least one AK lesion. This comparison takes similarity in demographics and climate into account.