Solar keratosis, also known as actinic keratosis or "sun spots", is a common skin condition caused by exposure to the sun. Typically small in size (usually smaller than a pencil eraser), a solar keratosis lesion is often red with a scaly or crusty layer. It usually develops many years after the exposure, and if untreated, a small percentage can go on to become skin cancer.
If detected early enough, it is usually easily treated without the need for surgery.