Actinic keratosis (AK) is a premalignant condition with thick, scaly, or crusty patches on the skin surface. Another name for actinic keratosis is called solar keratosis, sun spots, or precancerous spots. AK is slow growing and takes years to develop. It usually arises after age 40 but in some area with high intensity of sunlight such as Florida, AK can be seen in younger population. Fair-skinned people who have less protective pigment cell under their skin and who are frequently exposed to the sun are in higher risk for sun damage and developed actinic keratosis. If AK is not treated, it can progress into squamous cell carcinoma (skin cancer).