Corns & Callous - What are they are how do we get them? - Burchell & Associates - Podiatry

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Corns & Callous - What are they are how do we get them?

Corns and callous are one of the most common problems seen by Podiatrists.
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Corns and callouses are forms of hyperkeratosis, (thickening), of the epidermal, (top), layer of the skin, be it any where on the body, but generally on the hands and feet, in response to continual or intermittent trauma, pressure or friction, (rubbing).
The symptoms can vary from a mild burning sensation to an infected ulceration, typically under a corn on a toe.

The formation of thickened skin is a natural and normal way for the skin to react. The skin is reacting to excess pressure on an area that is unable to withstand that amount of force and is thickening to prevent wear & tear in the same way as we place patches on the knees of trousers and elbows of jackets to thicken the material.

A corn and callous should be regarded as an indication of another problem that is present rather than a condition in their own right.

The name "corn" comes from its appearance under the microscope. The hard part at the centre of the corn resembles a barley hare. Corn used to be a generic term for grain, and the name stuck. The scientific name is helloma, (plural hellomata).

A corn is a small, concentrated area of hard skin, usually in hairless and smooth skin that typically develops over a bony prominence, such as the apex of the toe, the top of the toe or between the toes. Because the pressure on the skin is greater over this area the cells of the skin are more compressed and become harder in structure. Corns are typically conical in shape with the base of the cone on the surface and the point of the cone deeper in the skin affecting deeper nerve endings, hence the intense pain of a corn. The conical shape follows the lines of pressure onto the skin where, typically, pressure starts from a wide angle down to a narrow point onto the bone.
There are five different types of corns. The two most common are hard and soft corns.

HARD CORNS, (helloma durum).
These are the most common and appear as concentrated areas of hard skin usually within a
wider area of thickened skin or callous, and can be symptoms of feet or toes not functioning
properly. They commonly occur on the top of the smaller toes or on the outer side of the little
toe. These are the areas where poorly fitted shoes tend to rub most or bad foot function can
cause excessive pressure.

SOFT CORNS, (helloma molle).
These develop in a similar way to hard corns; they are whitish and rubbery in texture where the skin becomes soft & moist from sweat that is unable to evaporate, or from inadequate drying, commonly between the 4th & 5th toes. They always appear between toes over one of the inter-phalangeal joints. In a good foot the joints in adjoining toes are staggered so when toes rub together there is no direct, excessive pressure over the bones, so the skin does not need to thicken to protect itself. This relationship is altered in deformed toes or a foot that over pronates.

SEED CORNS, (helloma mille).
These are tiny corns that tend to occur either singly or in clusters on the bottom of the foot, commonly under the 2nd metatarsal shaft or under the heel. They seem to be associated with friction and a dry skin. They can be usually painless. They can sometimes be "picked" out after a bath when the skin is soft.

These corns will bleed profusely if they are cut and can be very painful. They can be caused from a hard corn that is badly treated over a long period of time or where the pressure has been excessive without treatment for a long period and the skin structure has changed. They can sometimes be confused with verrucae.

These arise from corns that have been present for a long time. They appear to be more firmly attached to the deeper tissues than any other corn. They may also be painful..

What are callouses?
A callous is an especially toughened area of skin which has become realtively thick and hard as a response to repeated contact or pressure. As with a corn the body is protecting itself from excess wear and tear. Callous, the bodies' natural protection to excess wear and tear only becomes painful when it becomes too thick and this only happens when we do not naturally wear away the skin on the ground. Nature has not caught onto the evolution of us wearing shoes to protect our feet against the harsh surfaces we have created.
Callouses are larger, broader areas and have a less well defined edge than a corn. They tend to form on the underside of the foot and around the edges of the heels.

What is the treatment for callouses?
As the build up of hard skin is the bodies natural protection against excess wear and tear the cause of the problem needs to be addressed before nature will stop the callous building up. A certain amount of callous is needed to prevent wearing a hole in the skin so hard skin is normal, excess hard skin is abnormal.
Remove the pressure and/or correct the foot function and the callous will not build up.
Advice from a Podiatrist about all types of foot problems including the build up of callous is always the best first move.

Home Treatment.
Paring the skin away.
The most common type of home trestment is regular reduction of the skin using a pumice stone or hard skin file andthen using a foot cream to keep the skin soft and supple. This is an ongoing treatment since the cause cannot usually be addressed or identified at home, however it will keep an area relatively pain free but will not address the cause, usually a pair of shoes.
Corn Paints and Plasters.
Another treatment is the use of corn paints and plasters. These are a weak solution of Salicylic Acid that is designed to chemically burn the skin off in a liquid form in the case of the paint and a cream in the case of the plasters. Unfortunately the acid is not able to distinguish between hard skin and normal skin and the area can become inflammed and tender and in extreme circumstances an infection can occur. It should never be used if you have diabetes or poor circulation.
There are a large number of over the counter foot pads and gels available to help remove or redistribute pressure away from a particular area.

Podiatry Treatment.
A podiatric, (or chiropody), treatment will be able to identify the cause of the problem for you and offer treatment based on the cause.
Regular Maintenance.
If the cause of the problem is not able to be addressed then a regular podiatric treatment where the skin will be reduced on a regular basis with a scalpel to keep you comfortable and the skin soft and supple. This reduces the thickness and therefore the pressure on the underlying tissues. The length of time before the skin builds up again is dependant on many external factors but can range from 6 to 12 weeks.
Padding/Shoe Advice.
Padding can be applied to an affected area to keep the pressure away from the affected area or cushioning to reduce the pain and they can be tempoary or a longer lasting padding can be made and fitted. We can also advise on footwear, shoe stretching or try and address a foot function problem.
Insoles or Orthotics.  
Where there is a foot function cause in the gait cycle then an orthotic can be prescribed either over the counter of made to measure. These help to address a problem that the skeleton might have causing he foot to function in a slightly abnormal way.
In some cases where a foot deformity is creating a problem then surgery might be a better long term option. This is more often than not related to toe deformities such as a hammer toe or mallet toe. This can be very successful but not everyone is keen on surgery.
Corns can be painful.
Burchell & Associates - Core value podiatry.
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