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. It’s most commonly found on your face, lips, ears, back of your hands, forearms, scalp or neck. Also known as a solar keratosis, an actinic keratosis enlarges slowly and usually causes no signs or symptoms other than a patch or small spot on your skin.
https://www.mayoclinic.org/diseases-conditions/actinic-keratosis/symptoms-causes/syc-20354969

