The causes of filiform warts on the neck may be related to contact transmission, trauma, immunocompromised trauma and other factors. 1. contact transmission: the infectious source of this disease is filiform warts patients or HPV (human papillomavirus) carriers, mainly through direct contact or sharing personal belongings and other behaviors infected, if the above situation, may lead to filiform warts on the neck. 2. Trauma: If the skin around the neck is traumatized, the HPV virus may invade the body through the broken area and replicate and multiply, thus triggering the appearance of filiform warts. 3. low immune function: if the human body’s immune function is low, it may cause the resistance to become weak, unable to resist HPV virus invasion of the human body, thus triggering the disease. The reason for the filiform warts on the neck is different, it is recommended to go to the dermatology department of the hospital in time to get a clear cause, timely treatment.