There are several types of human warts.
All warts are benign tumors of the top layer of the skin, caused by distinct viruses .
We don't know why some people get warts and some don't. We assume it is due to variations in individual immune systems. Filiform warts are fingerlike, flesh-colored projections most commonly observed about the mouth, eyes, and nose. Generally they are numerous, found around the forehead, mouth, and the backs of the hands. Plantar warts are found on the soles of the feet.