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, well-defined, thickened area of skin that forms on the toes. Corns put pressure on the underlying skin against the bone. They are usually inflamed and painful.

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:
  • On hands:
    • Lifting weights
    • Using tools
    • Playing a stringed instrument
  • On feet:
    • Running long distances
    • Walking on hard surfaces without shoes
  • On knees: Kneeling to lay carpet or tile
• Corns—Any activity or condition that applies repeated friction or pressure to the skin over toes or other bones, including:
  • Presence of foot abnormality causing a protrusion that rubs against footwear
  • Wearing poorly-fitting shoes
  • Wearing socks that bunch around toes or with seams that rub against the toes

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
• Poorly-fitting footwear
• Foot deformities, such as bunion or hammer toe

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:

• A small, usually painful bump over bony prominence, on the side or the top of a toe, or between toes
• Yellow or reddish in color

Diagnosis

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

• Location—Corns usually only form over bony prominence, on a toe, or between toes; while calluses can form over any area where there is rubbing
• Degree of pain—Corns are usually quite painful, while calluses are usually painless or only slightly painful

A scalpel may be used to remove layers of the skin to make sure that it is a corn or callus, rather than a wart.

Treatment

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