Hello, verruca plana is a viral skin disease, and its pathogen, like verruca vulgaris, is caused by HPV53 infection.
Suggestion:
Oral antiviral drugs, such as valin, levamisole, vitamin B for injection12: transfer factor, fluorouracil ointment for external use, chlortetracycline ointment, etc. Severe cases can be treated with liquid nitrogen freezing or laser. Specifically, follow the doctor's advice