Dermatologically, a callus is an especially toughened area of skin, which has become relatively thick and hard (or callous) as a response to contact (rubbing and pressure). They are most usually found on the hand or foot, for obvious reasons. Calluses generally cause no harm, but may lead to other problems - infections, for example. Shoes that fit well can somewhat prevent calluses from forming on feet. Dermatology (from Greek derma, skin) is a branch of medicine dealing with the skin, its structure, functions, and diseases, as well as its appendages (nails, hair, sweat glands). ... Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system; which is composed of a layer of tissues that protect underlying muscles and organs. ... An infection is the detrimental colonization of a host organism by a foreign species. ... shoe for right foot A shoe is a piece of footwear for humans, less than a boot and more than a slipper. ...

Corns

Corns (also called clavi) are specially-shaped calluses that usually occur on thin or glabrous (hairless and smooth) skin surfaces, especially on the top of toes or fingers. Sometimes they do occur within the thicker palmar or plantar skin surfaces as well. They form when the pressure point against the skin traces an elliptical or semi-elliptical path. This forms a swirl of tissue, the center of which is at the point of pressure, gradually widening. There may be constant stimulation of the tissues in charge of producing corns, so even if the corn is removed or the pressure surgically removed, sometimes the skin may continue to grow corns for some time. In zootomy, several terms are used to describe the location of organs and other structures in the body of bilateral animals. ... In zootomy, several terms are used to describe the location of organs and other structures in the body of bilateral animals. ... In mathematics, an ellipse (from the Greek for absence) is a plane algebraic curve where the sum of the distances from any point on the curve to two fixed points is constant. ...

The name corn comes from its appearance under the microscope. The hard part at the center of the corn resembles a barley seed, that is, a funnel with a broad raised top and a pointed bottom. "Corn" used to be a generic term for grain, and the name stuck. The scientific name is heloma. Hard corns are called heloma durum, while soft corns are called heloma molle. Binomial name Hordeum vulgare L. Barley (Hordeum vulgare) is a major food and animal feed crop, a member of the grass family Poaceae. ...

The place of occurrence differentiates between soft and hard corns. Hard corns occur on dry, flat surfaces of skin. Soft corns (frequently found between two toes) stay moist, keeping the surrounding skin soft. The corn's center is not soft, however.

Development

Although most usually found on the foot (where the most pressure occurs), calluses can occur anywhere on the body as a reaction to moderate, constant "grinding" pressure. It is a natural reaction of the palmar or plantar skin. This article needs to be cleaned up to conform to a higher standard of quality. ...

For example, players of string instruments will develop calluses on their fingers with frequent play. This actually helps the player as the thicker skin protects the fingertips - extended play is often painful before the skin grown callous. If a beginning player plays too hard, however, a blister may be produced instead. A string instrument (also stringed instrument) is a musical instrument that produces sound by means of vibrating strings. ... A blister or bulla is a defense mechanism of the human body. ...

People with bunions may find painful calluses behind the second or third toes. These are caused by unequal pressure placed on the smaller toes. Such pressure-induced calluses can be very painful and often do not respond to trimming of the callus, soft materials, or orthotic devices. It is not the callus that causes pain, but rather the severe imbalance in the function of the foot that is taking its toll. In medicine, a bunion is a painful deformity of the bones and the joint between the foot and the big toe (the metatarsophalangeal (MTP) joint). ...

Shoes can produce corns by rubbing against the top of the toes or foot. Continued irritation may cause pain. Stretching the rubbing area of the shoe may reduce the pressure and stop the pain, but the corn may remain. If a toenail or a fingernail rubs against the skin, pinching it between surfaces for a period of time, a corn can form at the edge of the nail. These are difficult to treat because frequently the nail is the primary cause.

Sometimes a callus occurs where there is no rubbing or pressure. These hyperkeratoses can have a variety of causes. Some toxins, such as arsenic, can cause thick palms and soles. Some diseases, such as syphilis, can cause thickening of the palms and soles as well as pinpoint hyperkeratoses. There is a benign condition called keratosis palmaris et plantaris, which produces corns in the creases of the fingers and non-weight-bearing spaces of the feet. Some of this may be caused by actinic keratosis, which occurs due to overexposure to sun, or with age and hormonal shifts. Hyperkeratosis results when an excess of proteins called keratins are produced. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ... Depression-era U.S. poster advocating early syphilis treatment Syphilis (historically called lues) is a sexually transmitted disease (STD) that is caused by a spirochaete bacterium, Treponema pallidum. ... Actinic keratosis also called solar keratosis or senile keratosis is a premalignant condition of thick, scaly patches of skin. ...

Treatment

A common method, often done by a podiatrist, is to shave the calluses down, and perhaps pad them. A podiatrist (US English), or chiropodist (British English), is a podiatry professional, that is a person devoted to the study and treatment of disorders of the foot and ankle. ...

Most corns and calluses located under the foot are caused by the pressure of the foot's bones pressing against the skin, possibly preventing it from moving with the shoe or the ground. While well-fitting shoes will help some of these problems, occasionally some other degree of intervention is required to completely rid the foot of the problem. The most basic treatment is to put a friction-reducing insole or material into the shoe, or against the foot. On some cases, this will reduce the painfulness without actually making the callus go away.

In many situations, a change in the function of the foot by use of an orthotic device is required. This reduces friction and pressure, allowing the skin to rest and to stop forming protective skin coverings.

At other times, surgical correction of the pressure is needed. A typical modern surgery operation For other meanings of the word, see Surgery (disambiguation) Surgery (from the Greek cheirourgia - lit. ...

Diabetes

Diabetics face special skin challenges. Because diabetes affects the capillaries, the small vessels which feed the skin its blood supply, thickening of the skin increases the difficulty to supply nutrients to the skin. Additionally, the shear and pressure forces that cause corns and calluses may tear the capillaries, causing bleeding within the callus or corn. This article is about the disease that features high blood sugar. ... The word capillary is used to describe any very narrow tube or channel through which a fluid can pass. ... In physics and mechanics, shear refers to a deformation that causes parallel surfaces to slide past one another (as opposed to compression and tension, which cause parallel surfaces to move towards or away from one another). ...

Often, bleeding within the calluses is an early sign of diabetes, even before elevated blood sugars. Although the bleeding can be small, sometimes small pools of blood or hematoma are formed. The blood itself is an irritant, a foreign body within the callus that makes the area burn or itch. If the pool of blood is exposed to the outside, infection may follow. Infection may lead to ulceration. Luckily, this process can be prevented at several places, but such infections can become life-threatening. Diabetic foot infections are the leading cause of diabetic limb amputation. Hematoma on an elbow, nine days after a blood sample was taken A hematoma, or haematoma, is a collection of blood, generally the result of hemorrhage. ... An infection is the detrimental colonization of a host organism by a foreign species. ... An ulcer (from Latin ulcus) is an open sore of the skin, eyes or mucous membrane, often caused by an initial abrasion and generally maintained by an inflammation and/or an infection. ... Amputation is the removal of a body extremity by trauma or surgery. ...

See also

• hyperkeratosis

Hyperkeratosis results when an excess of proteins called keratins are produced. ...

External Links

• MayoClinic.com : Corns and calluses