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.
Calluses and corns form as protective pads of skin in response to repeated friction or pressure. Causes include:
Factors that may increase the risk of calluses and corns include:
Symptoms of calluses include:
Symptoms of corns include:
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:
A scalpel may be used to reveal the layers of the skin growth to make sure that it is a corn or callus, rather than a wart.
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. Self-treatment may lead to severe infection in these individuals.
Applying keratin-dissolving medication (such as salicylic acid) can help dissolve calluses and corns more quickly. Apply medication carefully, since it contains acid that may damage nearby healthy skin.
American Orthopaedic Foot and Ankle Society
Family Doctor—American Academy of Family Physicians
Canadian Orthopaedic Association
Canadian Orthopaedic Foundation
Callus. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated January 19, 2011. Accessed January 22, 2015.
Corn. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated June 10, 2010. Accessed January 22, 2015.
Corns. American Academy of Orthopaedic Surgeons website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00153. Updated September 2012. Accessed January 22, 2015.
Last reviewed January 2015 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.