Flat warts are benign growths caused by human papillomavirus (HPV) infection of the skin’s mucous membranes. The actual warts can be treated by means of medication, intramuscular injections, and physical therapy. 1. Apply drugs: flat warts will lead to skin keratosis, you can apply salicylic acid cream to promote epidermal exfoliation, or through the application of retinoic acid cream to regulate the proliferation of epithelial cells to achieve the purpose of treatment. 2. Intramuscular injection of drugs: patients can also under the guidance of the doctor intramuscular injection of interferon and other drugs to reduce the occurrence of flat warts. 3. Physical therapy: if the drug can not achieve a better treatment effect, you can also through the liquid nitrogen freezing treatment, laser treatment and other ways to alleviate the symptoms.