Fluorouracil cream and topical solution are used to treat actinic or solar keratoses (scaly or crusted lesions [skin areas] caused by years of too much exposure to sunlight). Fluorouracil cream and topical solution are also used to treat a type of skin cancer called superficial basal cell carcinoma if usual types of treatment cannot be used. Fluorouracil is in a class of medications called antimetabolites.