Alternate Names : Calluses and corns
Corns and calluses are thickened layers of skin caused by repeated pressure or friction.
Overview, Causes, & Risk Factors
Corns and calluses are caused by pressure or friction on skin. A corn is thickened skin on the top or side of a toe, usually from shoes that do not fit properly. A callus is thickened skin on your hands or the soles of your feet.
The thickening of the skin is a protective reaction. For example, farmers and rowers get callused hands that prevent them from getting painful blisters. People with bunions often develop a callus over the bunion because it rubs against the shoe.
Neither corns nor calluses are serious conditions.
Pictures & Images
Corns and calluses
Corns and calluses form on the skin because of repeated pressure or friction. A corn is a small, tender area of thickened skin that occurs on the top or side of a toe. A callus is a rough, thickened area of skin that appears because of repeated irritation or pressure to an area of skin. Calluses usually develop on the palms of the hand and soles of the feet.
The skin is the largest organ of the body. The skin and its derivatives (hair, nails, sweat and oil glands) make up the integumentary system. One of the main functions of the skin is protection. It protects the body from external factors such as bacteria, chemicals, and temperature. The skin contains secretions that can kill bacteria and the pigment melanin provides a chemical pigment defense against ultraviolet light that can damage skin cells. Another important function of the skin is body temperature regulation. When the skin is exposed to a cold temperature, the blood vessels in the dermis constrict. This allows the blood which is warm, to bypass the skin. The skin then becomes the temperature of the cold it is exposed to. Body heat is conserved since the blood vessels are not diverting heat to the skin anymore. Among its many functions the skin is an incredible organ always protecting the body from external agents.
Review Date : 7/10/2009
Reviewed By : Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Dept of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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