A corn is a small, painful, raised bump on the outer skin layer. A callus is a rough, thickened patch of skin.
Description
Corns and calluses are one of the three major foot problems in the United States. The other two are foot infections and toenail problems. Corns and calluses affect about 5% of the population.
Corns usually appear on non-weight-bearing areas like the outside of the little toe or the tops of other toes. Women have corns more often than men, probably because women wear high-heeled shoes and other shoes that do not fit properly. Corns have hard cores shaped like inverted pyramids. Sharp pain occurs whenever downward pressure is applied, and a dull ache may be felt at other times.
Calluses occur most often on the heels and balls of the feet, the knees, and the palms of the hands. However, they can develop on any part of the body that is subject to repeated pressure or irritation. Calluses are usually more than an inch wide—larger than corns. They generally don't hurt unless pressure is applied.
Types of corns
A hard corn is a compact lump with a thick core. Hard corns usually form on the tops of the toes, on the outside of the little toe, or on the sole of the foot.
A soft corn is a small, inflamed patch of skin with a smooth center. Soft corns usually appear between the toes.
A seed corn is the least common type of corn. Occurring only on the heel or ball of the foot, a seed corn consists of a circle of stiff skin surrounding a plug of cholesterol.
Types of calluses
A plantar callus, a callus that occurs on the sole of the foot, has a white center. Hereditary calluses develop where there is no apparent friction, run in families, and occur most often in children.
Causes and symptoms
Corns and calluses form to prevent injury to skin that is repeatedly pinched, rubbed, or irritated. The most common causes are:
shoes that are too tight or too loose, or have very high heels
tight socks or stockings
deformed toes
walking down a long hill, or standing or walking on a hard surface for a long time
Jobs or hobbies that cause steady or recurring pressure on the same spot can also cause calluses.
Symptoms include hard growths on the skin in response to direct pressure. Corns may be extremely sore and surrounded by inflamed, swollen skin.
Diagnosis
Corns can be recognized on sight. A family physician or podiatrist may scrape skin off what seems to be a callus, but may actually be a wart. If the lesion is a wart, it will bleed. A callus will not bleed, but will reveal another layer of dead skin.
Treatment
Corns and calluses do not usually require medical attention unless the person who has them has diabetes mellitus, poor circulation, or other problems that make self-care difficult.
Treatment should begin as soon as an abnormality appears. The first step is to identify and eliminate the source of pressure. Placing moleskin pads over corns can relieve pressure, and large wads of cotton, lamb's wool, or moleskin can cushion calluses.
Using hydrocortisone creams or soaking feet in a solution of Epsom salts and very warm water for at least five minutes a day before rubbing the area with a pumice stone will remove part or all of some calluses. Rubbing corns just makes them hurt more.
Applying petroleum jelly or lanolin-enriched hand lotion helps keep skin soft, but corn-removing ointments that contain acid can damage healthy skin. They should never be used by pregnant women or by people who are diabetic or who have poor circulation.
It is important to see a doctor if the skin of a corn or callus is cut, because it may become infected. If a corn discharges pus or clear fluid, it is infected. A family physician, podiatrist, or orthopedist may:
inject cortisone into the affected area to decrease pain or inflammation
perform surgery to correct toe deformities or remove bits of bone
Alternative treatment
Standing and walking correctly can sometimes eliminate excess foot pressure. Several types of bodywork can help correct body imbalances. Bodywork is a term used for any of a number of systems, including Aston-Patterning, the Feldenkrais method, and rolfing, that manipulate the body through massage, movement education, or meditational techniques.
Aloe (Aloe barbadensis) cream is an effective skin softener, and two or three daily applications of calendula (Calendula officinalis) salve can soften skin and prevent inflammation. One teaspoon of lemon juice mixed with one teaspoon of dried chamomile (Martricaria recutita) tea and one crushed garlicclove dissolves thickened skin.
An ayurvedic practitioner may recommend the following treatment:
apply each day a paste made by combining one teaspoon of aloe vera gel with half that amount of turmeric (Circuma longa)
massage gently with mustard (Brassica cruciferae) oil
Prognosis
Most corns and calluses disappear about three weeks after the pressure that caused them is eliminated. They are apt to recur if the pressure returns.
Extreme pain can change the way a person stands or walks. Such changes can, in turn, cause pain in the ankle, back, hip, or knee.
Bursitis, a painful, inflamed fluid-filled sac, can develop beneath a corn. An ulcer or broken area within a corn can reach to the bone. Infection can have serious consequences for people who have diabetes or poor circulation.
Prevention
Corns and calluses can usually be prevented by avoiding friction-causing activities and wearing shoes that fit properly, are activity-appropriate, and are kept in good repair. Soles and heels that wear unevenly may indicate a need for corrective footwear or special insoles. Socks and stockings should not cramp the toes. Gloves, kneepads, and other protective gear should also be worn as needed.
Feet should be measured, while standing, whenever buying new shoes. It is best to shop for shoes late in the day, when feet are likely to be swollen. It is also important to buy shoes with toe-wiggling room and to try new shoes on both feet.
BOOKS
The Editors of Time-Life Books. The Medical Advisor: The Complete Guide to Alternative and Conventional Treatments. Alexandria, VA: Time Life, Inc., 1996.
New Choices in Natural Healing. Ed. Bill Gottlieb, et al. Emmaus, PA: Rodale Press, 1995.
ORGANIZATIONS
American Podiatric Medical Association. 9312 Old Georgetown Road, Bethesda, MD 20814-1698. (301) 571-9200. <http://www.apma.org>.
OTHER
"Corn or Callus." ThriveOnline. 20 Apr. 1998 <http://thriveonline.oxygen.com>.
"Foot Disorders." Foot Talk Home Page. <http://www.foottalk.com/corns.htm>.
"Foot Facts." American Podiatric Medical Association. 20 Apr. 1998 <http://www.apma.org>.
Maureen Haggerty
KEY TERMS
Ayurveda—Ayurveda is a system of wholistic medicine from India that aims to bring the individual into harmony with nature. It provides guidance regarding food and lifestyle, so that healthy people can stay healthy and people with health challenges can improve their health.
Bursitis—Inflammation of a bursa, a fluid-filled cavity or sac. In the body, bursae are located at places where friction might otherwise develop.
