Corns and calluses are areas of thick skin that result form excessive pressure or friction over a boney prominence. When these areas develop on the bottom of the foot they are called calluses. When they occur on the top of the toes they are called corns. They can also occur between the toes, the back of the heels and the top of the foot. The thickening of the skin is a normal body response to pressure or friction. Often times they are associated with a projection of bone called a bone spur. Not all areas of thickened skin are corns or calluses. Planter’s warts, inclusion cysts and porokeratoses also cause a discreet thickening of the skin that resembles corns and calluses.