Actinic keratoses are rough, scaly lesions that develop on the skin after years of exposure to ultraviolet rays, according to the Skin Cancer Foundation. They typically appear on the scalp, face, hands and lips.
Actinic keratoses are often raised, red in color and similar in appearance to warts, notes the Skin Cancer Foundation. They primarily affect people over the age of 50 and are more likely to develop in people with fair skin, red or blond hair, and green, gray or blue eyes. Although most are benign, up to 10 percent of actinic keratoses develop into squamous or basal cell carcinomas without proper treatment.