corns and calluses, thickenings of the outer layer of skin where there is irritation or constant pressure. Corns are cone-shaped with their points protruding into the dermis, or inner layer of skin. They usually have hard, shiny surfaces surrounded by red, painful areas. Soft-surfaced corns sometimes develop between overlapping toes where there is an accumulation of moisture. Treatment of corns is directed at the relief of irritation or pressure, e.g., wearing properly fitted shoes; they can also be softened by pastes and ointments or removed by a physician. Calluses typically involve only the outermost layers of skin and are not usually painful; they tend to disappear once the source of irritation has been removed. See bunion.