Plantar warts are caused by the human papillomavirus (HPV). The virus usually enters the foot through small cuts or breaks in the skin. It is also possible to contract the virus by walking barefoot in places that are warm and damp.
Most plantar warts are small and uncomfortable. They can be painful when standing or walking and will usually form a callus. Plantar warts often form in a cluster, although it is possible to have only one. In some cases, a cluster can cover a large portion of the sole. Black pinpoints, which are small clotted blood cells, may also appear.
Physicians are able to diagnose a plantar wart by examining the foot and reviewing symptoms. In some cases, a shave biopsy may be necessary to remove a small portion of the lesion for lab analysis.
Plantar warts generally do not require treatment and will eventually go away on their own. If the warts are painful or spreading, they may be removed using over the counter medications. In severe cases, painful and unsightly warts can be removed by a medical professional.