1911 Encyclopædia Britannica/Corn (skin growth)
CORN (from Lat. cornu, horn), in pathology (technically clavus), a localized outgrowth of the epidermic layer of the skin, most commonly of the toe, with a central ingrowth of a hard horny plug. The underlying papillae are atrophied, causing a cup-shaped hollow, whilst the surrounding papillae are hypertrophied. The condition is mainly caused by badly fitting boots, though any undue pressure, of insufficient power to give rise to ulceration, may be the cause of a corn. Corns may be hard or soft. The hard corn usually occurs on one of the toes, is a more or less conical swelling and may be extremely painful at times. If suppuration occurs around the corn, it is apt to burrow, and if unattended to may give rise to arthritis or even necrosis. The best treatment is to soften the corn with hot water, pare it very carefully with a sharp knife, and then paint it with a solution of salicylic acid in collodion. The painting must be repeated three times a day for a week or ten days. The soft corn occurs between the toes and is usually a more painful condition. Owing to the absorption of sweat its surface may become white and sodden in appearance. The treatment is much the same, but spirits of camphor should be painted on each night, and a layer of cotton wool placed between the toes during the daytime.