Flat warts are mainly due to human papilloma virus infection, face long flat warts often appear in the face of green beans to soybean size brown flat papules, smooth surface, round, oval and so on. The most common treatments include physical therapy (e.g., laser therapy, liquid nitrogen therapy, etc.) and topical medication. 1. Physical therapy: including laser therapy and liquid nitrogen cryotherapy. Under local anesthesia, flat warts can be removed by laser cauterization, and there will be slight pain after the treatment, which can be relieved in a short period of time. The actual warts can also be removed by means of liquid nitrogen freezing, which is a painless and effective treatment. 2. topical medication: you can use retinoids, salicylic acid ointment, fluorouracil cream and other medications under the guidance of a doctor.