Multiple actinic keratoses on the head of an 69 year old male patient. This is a precancerous skin growth caused by sun damage. Actinic keratoses are mostly found on areas of skin that are exposed to the sun most often, including the backs of hands and the face. It is important to remove the lesions as they can develop into skin cancer. They may be removed by scraping, freezing with liquid nitrogen, drugs, or surgery.