what are white crusty spots on skin?
Actinic keratosis. Actinic keratoses are scaly spots or patches on the top layer of skin. With time the spots or patches may become hard with a wartlike surface. An actinic keratosis (ak-TIN-ik ker-uh-TOE-sis) is a rough, scaly patch on your skin that develops from years of exposure to the sun.