Warts and corns are two common foot conditions that are often confused. Warts can appear all over the body, but corns appear only on the feet. Corns are typically caused by a bone in the foot causing pressure on another part of the foot, or your shoe. They often appear on the top of or between toes. The skin becomes hard where the pressure occures. This thickened skin can press deep into the skin and become painful. A corn is not an infection – they are not contagious. A wart is a viral infection that can be contagious and can spread and multiply, often appearing in clusters. Warts that occur on the bottom of the foot (or plantar surface) are known as plantar warts. They often have small black dots on their surface. Warts can be treated much more easily before they spread.