A callus is an abnormal thickening of the top layer of skin, which is composed of the natural protein, keratin. Calluses can form on body surface 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, and they are usually very 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:

• Weight lifting (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

A risk factor is something that increases your chance of getting a disease or condition.

• 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 or burning sensation

• Yellow or reddish in color

Symptoms of corns include:

• Small, usually very painful bump on the side, on the top, 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. Calluses are usually painless or only slightly painful.

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 of corns or calluses. For these people, self-treatment may lead to severe infection.

Prevention

To prevent calluses:

• Avoid activities that apply repeated friction or pressure to the skin.

• Or, 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

RESOURCES:

American Academy of Family Physicians
http://www.aafp.org

The American Orthopaedic Foot and Ankle Society
http://www.aofas.org

References:

American Academy of Orthopaedic Surgeons. Available at: http://www.aaos.org/.

The Merck Manual of Medical Information—Home Edition. Simon and Schuster, Inc.; 2000.