Actinic keratosis is a fairly common skin condition. It is also known as solar keratosis.  Actinic keratosis disease is a rough and often bumpy patch or lesion that forms on the skin. Typically, actinic keratosis is found on the scalp, back of the hands, the face, ears, back of the forearms, the neck, and the shoulders. The size of actinic keratosis varies from tiny to an inch or more in diameter. Similarly, color variations range from light to dark with variations throughout the patches.