What is Actinic Keratosis? Also called solar keratosis Actinic keratoses (AKs): AKs form on skin that soaks up lots of sun over the years. An actinic keratosis (ak-ti-nik ker-ah-TOE-sis), or AK, is a rough, dry, scaly patch or growth that forms on the skin. An AK forms when the skin is badly damaged by ultraviolet (UV) rays from the sun or indoor tanning. Most people get more than one AK. When you have more than one AK, you have actinic keratoses, or AKs. AKs are very common and one of the most frequent reasons for seeing a dermatologist. Anyone who