Fluorouracil ointment can be used for the treatment of flat warts, but it can leave pigmentation after use, so flat warts on the face should be used with caution. Fluorouracil ointment can inhibit RNA synthesis, suitable for the treatment of warts, applicable to the treatment of hyperkeratosis, wart-like damage and white patches, can also be used to treat flat warts. However, it should be noted that the drug may leave discoloration after use, so the face should avoid using this drug. Contraindications to the use of the drug include pregnant women in the first trimester of pregnancy, people with chickenpox or shingles, debilitated patients, and breastfeeding is prohibited for lactating women who use the drug. Adverse reactions such as nausea, loss of appetite or vomiting, oral mucositis or ulcers, abdominal discomfort or diarrhea may occur after use of the drug. Flat warts are mainly caused by human papilloma virus infection, in addition to fluorouracil ointment, you can also use salicylic acid ointment, retinoic acid ointment and other drugs for treatment; warts number is small, you can choose to freeze, laser, electrocautery and other means of treatment. The specific use of drugs should be under the guidance of a specialist physician, not unauthorized use of drugs.