What is Actinic Keratosis (AK) ?

Learn Actinic Keratosis (AK) Meaning and Definition Actinic keratosis (AK) is a common skin condition characterized by rough, scaly patches or small growths on the skin’s surface, typically caused by long-term exposure to ultraviolet (UV) radiation from the sun or tanning beds. These patches can be precancerous and may develop into squamous cell carcinoma if left untreated.