This is a thickened condition of the epidermis or scarfskin. It is most likely to occur over joints and the prominent points of bones. It is generally produced by prolonged pressure. Its object is the protection of the sensitive parts beneath from injury. A callus does not usually require treatment except when the part becomes inflamed. The proper treatment is soaking in very hot water for fifteen or twenty minutes three or four times a day, and the wearing of a poultice or wet compress the balance of the time.

Corns are modifications of the callus, the treatment of which is deferred to the section on surgery.