How are flat warts caused and how can they be removed?

Flat warts are benign skin growths caused by infection with human papillomavirus (HPV). Their development is associated with multiple factors including viral infection, immune status, and skin injuries. HPV spreads through skin-to-skin contact. After infecting skin cells, the virus causes cell proliferation, keratinization, and hyperplasia, eventually leading to the formation of flat warts. To remove flat warts, several treatment methods are available, mainly including: 1. Medication therapy: Topical retinoid medications (such as tretinoin cream) and antiviral agents (such as recombinant human interferon α-2b gel). These medications promote epidermal cell renewal and inhibit viral replication, thereby achieving therapeutic effects. 2. Physical therapy: Such as liquid nitrogen cryotherapy and laser treatment. These modalities destroy flat wart tissue through physical means, causing it to necrose and shed. 3. Surgical treatment: For larger flat warts, surgical excision may be considered. 4. Traditional Chinese medicine (TCM) therapy: Including external washing with herbal medicine, acupoint injection, and acupuncture. These methods are conducted according to TCM theory and have demonstrated certain therapeutic efficacy.