EFUDEX cream is used to treat certain skin problems, including cancer or conditions that could become cancerous if not treated. EFUDEX cream is used to treat scaly overgrowths of skin (actinic or solar keratoses). EFUDEX cream may also be used in the treatment of superficial basal cell carcinoma. It works by interfering with the growth of skin cells. Fluorouracil works by causing the death of cells which are growing fastest, such as abnormal skin cells.