Corns and calluses: Symptoms, diagnosis and treatment

What is a corn? What is a callus?

Corns and calluses can be annoying, but your body actually forms them to protect sensitive skin. Corns and calluses are often confused with one another.

Corns generally occur on the tops and sides of the toes. A hard corn is a small patch of thickened, dead skin with a small plug of skin in the centre. A soft corn has a much thinner surface, appears whitish and rubbery, and usually occurs between the toes. Seed corns are clusters of tiny corns that can be very tender if they are on a weight-bearing part of the foot. Seed corns tend to occur on the bottom of the feet, and some doctors believe this condition is caused by blocked sweat ducts.

Calluses are hard and rough-feeling areas of skin that can develop on hands, feet or anywhere there is repeated friction - even on a violinist's chin. Like corns, calluses have several variants. The common callus usually occurs when there has been a lot of rubbing against the hands or feet. A plantar callus is found on the bottom of the foot.

What causes corns and calluses?

Some corns and calluses on the feet develop from an improper walking motion, but most are caused by ill-fitting shoes. High-heeled shoes are the worst offenders. They put pressure on the toes and make women four times as likely as men to have foot problems. Other risk factors for developing a corn or callus include foot deformities and wearing shoes or sandals without socks, which leads to friction on the feet.

Rubbing or pressure can cause either soft corns or plantar calluses. If you or your child develops a callus that has no clear source of pressure, have it looked at by a doctor or a podiatrist, since it could be a wart or be caused by a foreign body - such as a splinter - trapped under the skin. Feet spend most of their time in a closed, moist environment, which is ideal for breeding fungal and bacterial infections. Staph (bacterial) infections can start when bacteria enter corns through breaks in the skin and cause the infected skin to discharge fluid or pus.

What are the symptoms of corns and calluses?

• A callus is a patch of compact, dead skin anywhere on the body that is subject to friction. There are different common names given to various types of calluses.
• A hard corn is a compact patch of hard skin with a dense core, located on top of a toe or the outside of the little toe.
• A soft corn is a reddened, tender area of skin, has a thin, smooth centre and is found between toes.
• A seed corn is a plug-like circle of dead skin, often painful, on the heel or ball of the foot.
• A plantar callus is a callus on the bottom - or plantar - surface of the foot.