An actinic keratosis (AK) is a scaly or crusty bump that forms on the skin surface occasionally they will itch or produce a prickling or tender sensation. These lesions are most likely found on the face, ears, bald scalp, neck, back of hands, forearms and lips. AK can be the first step in the development of skin cancer and therefore is a precursor of cancer or precancer. There are a number of effective treatments depending on the lesion, age and health. Some of these treatments include: Cryosurgery and topical creams.