Friction between the foot and the floor is important in walking and running. Friction allows us to stand in place without slipping and to push off during the normal gait cycle. Each step we take results in friction that can irritate the ball of the foot, the toes, and heel. In a response to friction, skin will often thicken to form a protective outer layer. We call this thickening a corn or callus. Corns and calluses come in all shapes, sizes, and varieties. The terms corn and callus can be used interchangeably, but classically, a corn is a build-up of skin on the tops or sides of one or more toes while a callus is an area of thickened skin on the bottom of the foot or heel. Corns and calluses are found equally between men and women and are more common as we age.
When skin senses a mechanical irritation it responds by thickening and forming a callus. Mechanical irritation could be due to a shoe that is too tight. It could be friction against the ground or it could even be the mechanical irritation that occurs between two adjacent toes. The formation of callus as a response to friction is initially considered to be a helpful, protective response, but as the skin continues to thicken it becomes painful. In most cases, corns and callus form by the mechanical irritation (friction) of the skin.
One of the more common types of corns is due to contraction of the toe (hammer toe) placing pressure on the top of the toe from the toe box of the shoe. This type of corn is referred to as a helloma dura (HD), or hard corn. Soft corns, on the other hand, are found between the toes. Soft corns occur most commonly between the 4th and 5th toes and exhibit soft, white, macerated tissue between the toes. Soft corns, also known as HM's (helloma molle) or kissing corns, are commonly misdiagnosed as a chronic athlete's foot infection.
Examples of the types of corns and calluses found in foot care include:
Heloma dura - hard corn
Heloma molle - soft corn
Heel fissures - callus found surrounding the rim of the heel
HD - heloma dura, or hard corn commonly found on the tops of toes
HM - helloma molle, also known as a soft corn and found between the toes
Interdigital corns - corns found between the toes
IPK - intractable plantar keratoma
Kissing corns - also known as an HM and found between the toes
Lister's Corn - a corn found adjacent to the 5th toenail. Very common on the outside of the little toenail and appears to look like a second toenail.
Pinch callus - callus found on the plantar medial aspect of the great toe
Soft corn - found between the toes. most often between the 4th and 5th toes. Also called an HM.
Spin callus - see pinch callus
Tyloma - callus found on the plantar forefoot beneath the metatarsal heads
Causes and contributing factors
Tight or poorly-fitting shoes are the single most common contributing factor to corns and callus of the feet. Irregularly shaped feet and toes may be difficult to properly fit into shoes and may require fitting help from a pedorthist or podiatrist.
Many corn and callus problems are due to poorly-fitting shoes. The foot is the square peg that just doesn't fit into the round hole (the shoe.) Treatment choices include wearing wider, softer shoes or surgically altering the foot to fit the shoe. A corn pad can also be used to cushion the corn. Conservative care is very successful at treating corns and callus but does require ongoing maintenance of the problem.
The portion of the shoe that covers the toes is called the toe box. The width and depth of the toe box are very important when trying to obtain a good fit. An improperly fit toe box can contribute to the formation of corns. Try this simple test. Stand barefoot on the floor. Place your shoe on the floor right next to your foot. Now compare the shape of your forefoot and the shape of the toe box. If the two are incompatible, friction on the toes may result in a corn.
Corn pads and callus pads come in all kinds of shapes and sizes. Choosing the correct pad depends upon three things: (1) the location of the corn or callus (2) the type of shoe in which you intend to wear the pad and (3) the activity you plan to participate in while wearing the pad. Soft corns respond to the use of a pad that separates the toes. Soft corn pads can be made from silicone gel, soft foam or lamb's wool. Many folks find relief with a simple cotton ball that’ll separate the toes. Foam and gel toe sleeves are a popular solution for hard corns. Hard corns can also be treated with gel cushions and adhesive-backed felt "cut out" pads.
Periodic paring (debridement) of a hard corn can help to reduce the thickness of the callus. This can be accomplished with a safety razor, callus file or pumice stone. Topical callus creams can also be used to soften callus prior to debridement. Care should be exercised with medicated callus creams in patients with poor circulation, diabetes or loss of sensation (peripheral neuropathy.)
Permanent correction of corns can be accomplished by a number of different surgical procedures. The procedures vary dramatically, based upon the type and location of the corn. Your podiatrist can help you determine whether you may be a candidate for surgical correction of your corn.
When to contact your doctor
If you find difficulty treating corns and callus, a visit to the doctor may be indicated. A single visit to your podiatrist can often help to orient you to new and more effective methods of treatment for corns and callus. Any skin lesion that appears suddenly or that is painful should be evaluated by your podiatrist for possible biopsy to rule out malignancy.
Author(s) and date
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Cite this article as: Oster, Jeffrey. Corn and Callus. http://www.myfootshop.com/article/corn-and-callus
Most recent article update: March 7, 2018.
Corn and Callus by Myfootshop.com is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.
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