Warts are caused by a virus which enters the skin and begins to grow into a small mass. Warts on the sole of the foot often have and overlying callus and can be painful to walk on. They often appear as a bump in the skin and may have small black dots in the center. Warts can be treated in a variety of way using chemicals, freezing or a new method called Photodynamic Therapy.
Photodynamic Therapy was first developed for cancer treatment. It involves removing the overlying callus, application of a photosensitizing compound and applying a specific wavelength of light to the area. The light causes the photosensitizer to react with the exposed tissue, killing the wart. PDT can also be used for treatment of fungal nails.