Discussion
The above results show PAI is effective and safe to treat subungual warts. In addition, it has been reported that PAI can effectively eliminate different types of HPV infection[4]. PAI is a compound preparation of Chinese traditional medicine, containing Fructus Cnidii, Honeysuckle, and Sophora flavescens[5]. At present, it is considered that PAI can quickly cross the epidermal cell space to reach the basal layer of the epidermis without damaging the dermis and the subcutaneous tissue, the mechanism of PAI maybe the exfoliation of epidermal cells[4-6].