Is flat warts caused by HPV infection?

Flat warts are indeed caused by infection with the human papillomavirus (HPV). There are multiple subtypes of HPV, among which HPV type 3 is the primary virus responsible for flat warts. Other subtypes, such as HPV 10 and 28, may also lead to the development of flat warts. These viruses are mainly transmitted through skin contact, such as direct contact with the skin of an infected individual or sharing personal items with an infected person. Flat warts commonly occur on the face, back of the hands, and forearms. They present as localized, firm, flat papules that are skin-colored or yellowish-brown. Self-scratching may sometimes cause their spread. Therefore, key measures for preventing flat warts include maintaining skin hygiene, avoiding contact with the skin of infected individuals, and enhancing one's own immune system.