Actinic keratoses, also known as solar keratoses or sun spots, are rough, scaly patches of skin appearing in sun-exposed areas. They are pre-cancerous, and are a sign of excessive UV exposure. Sometimes, they can turn into a type of skin cancer called a squamous cell carcinoma.
Treatment options include liquid nitrogen or cryotherapy, creams such as 5-fluorouracil, imiquimod, and diclofenac, and photodynamic therapy.