Definition

A callus is an abnormal thickening of the top layer of skin, which is composed of the natural protein, keratin. Calluses can form on areas that are repeatedly exposed to friction or pressure. They are usually painless or only mildly painful.

A corn is a small, thickened area of skin that forms on the toes. Corns put pressure on the underlying skin against the bone. They are usually painful.

A Corn

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Causes

Calluses and corns form as protective pads of skin in response to repeated friction or pressure. Causes include:

• Calluses—Any activity that applies repeated friction or pressure to an area of skin, including:
  • Lifting weights (hands)
  • Using tools (hands)
  • Playing a stringed instrument (hands)
  • Running long distances (feet)
  • Kneeling to lay carpet or tile (knees)
  • Walking on hard surfaces without shoes (feet)
• Corns—Any activity or condition that applies repeated friction or pressure to the toes, including:
  • Wearing ill-fitting shoes
  • Bunching of socks around toes
  • Socks with seams that rub against the toes
  • Foot abnormality causing a protrusion that rubs against footwear

Risk Factors

Factors that may increase the risk of calluses and corns include:

• Professions or physical activities that cause repeated friction or pressure on the skin
• Wearing ill-fitting footwear

Symptoms

Symptoms of calluses include:

• Rough, thickened area of skin
• Painless or slight degree of pain, burning sensation
• Yellow or reddish in color

Symptoms of corns include:

• Small, usually painful bump on the side or the top of the toe, or between toes
• Yellow or reddish in color

Diagnosis

The doctor will examine the skin where a corn or callus has formed. Diagnosis is based on symptoms and visual observation of the corn or callus. They are easily distinguished by:

• Location—Corns usually only form on or between the toes.
• Degree of pain—Corns are usually quite painful, while calluses are usually painless or only slightly painful.

The doctor may need to use a scalpel to reveal the layers of the skin growth to make sure that it is a corn or callus, rather than a wart.

Treatment

Treatment of calluses and corns usually includes self-care and medication. In severe cases, minor surgery may be necessary. People with diabetes or circulatory problems should always see a medical doctor or podiatrist for treatment. Self-treatment may lead to severe infection in these individuals.

Prevention

To prevent calluses:

• Avoid activities that apply repeated friction or pressure to the skin.
• Wear gloves, thick socks, or padding over the affected area of the skin.

To prevent corns:

• Wear properly fitted shoes.
• Wear properly fitted socks with no irritating stitching.