A method for treating actinic keratosis or basal cell carcinoma. A person's skin is inspected to identify areas that exhibit lesions indicating actinic keratosis or basel cell carcinoma. If such areas are found, a treating composition is applied to the skin in that area. The treating composition may include avobenzone, octocrylene, octyl salicylate, and oxybenzone, and optionally may additionally include SD alcohol 40, C12-15 alkyl benzoate, acrylates, octylacrylamide copolymer, hydroxypropyl cellulose, PEG-40 sorbitan peroleate, tocopherol, and aloe barbadensis extract. The skin is monitored regularly to determine whether the skin lesions remain, and the treating composition is applied several times daily for a period of at least two months until the area is substantially free of the lesions.
