Actinic keratosis (AK) is the most common precancer that forms on skin damaged by chronic exposure to ultraviolet (UV) rays from the sun and/or indoor tanning. Solar keratosis is another name for the condition.

Detecting an actinic keratosis (AK) early gives you the opportunity to treat the lesion and prevent skin cancer before it starts. When diagnosed promptly, almost all actinic keratoses (plural) can be successfully removed. Left untreated, some AKs may progress to squamous cell carcinoma (SCC).