Plantar warts occur on the sole of the foot and look like calluses. They result from an infection by a specific virus. They are like warts elsewhere, but they grow inward. The wart cannot grow outward because of weight placed on it when you stand. You may experience severe pain when walking, and can have just one or many plantar warts.
Plantar warts are extremely difficult to treat, but success has been achieved with repeated applications of salicylic acid (available over the counter) to soften the overlying callus and expose the virus. Other treatments include injection of the warts with medication, freezing the warts with liquid nitrogen and, very rarely, surgery.
Your podiatrist is a Doctor of Podiatric Medicine (DPM) with extensive training in the treatment of the entire foot and ankle including bones, joints, ligaments, tendons, muscles, and nerves.