Ointments for flat warts include imiquimod cream, fluorouracil ointment, and retinoic acid ointment. 1. Imiquimod cream: this ointment can activate immune cells to produce cytokines to exert indirect antiviral effects. A few people may have some adverse reactions, such as localized skin erythema, edema and burning. 2. Fluorouracil ointment: this medication can interfere with viral synthesis, but it may cause hyperpigmentation and is generally not recommended for use on the face. 3. Vitamin A acid ointment: this drug can regulate epidermal keratinization, inhibit epidermal hyperplasia, make the over-keratinized stratum corneum cells loose off, so as to achieve the effect of removing warts. However, it may cause adverse reactions such as burning, erythema or flaking. Specifically should be under the guidance of a doctor to regulate the use of drugs, can not be used casually to avoid adverse reactions.