Corns and callus are one of the most common problems seen by Podiatrists. They can occur on any part of the foot and vary in symptoms from a mild callus under the foot, to an infected ulcer that can develop under a corn on a toe. Other names for corns and callus are hyperkeratosis, clavus, heloma and tyloma.
Pathologically they are all the same - the skin has thickened in response to pressure. A callus generally refers to a more diffuse thickening of the skin (more common on the toes, but can occur under the ball of the foot) whereas a corn is a thicker, more focal area (more common on the toes). A corn can occur under and be surrounded by callus.
A corn or callus are areas of thickened skin that occur in areas of pressure. They are actually a normal and natural way for the body to protect itself. For example, callus develops on the hand when chopping a lot of wood - it's a normal way for the skin to protect itself. In the foot, the skin will thicken up to protect itself when there are areas of high pressure. The problem occurs when the pressure continues, so the skin gets thicker. It eventually becomes painful and is treated as something foreign by the body.
Corns appear as a thickening of the skin on the toes. This thickening appears as a cone-shaped mass pointing down into the skin. Hard corns are usually located on the outer surface of the little toe or on the upper surface of the other toes, but can occur between the toes. A soft corn occurs between the toes and are kept soft by the moisture in this area. A callus is a more diffuse area of thickening and does not have the focal point of the corn.
Corns and callus are caused by one thing - TOO MUCH PRESSURE, usually in combination with some friction. There is no other way to get them - the pressure stimulates the skin to thicken to protect itself, but as the stimulation of the pressure continues, it becomes painful.
Too much pressure can be from causes such as:
As there are a number of problems that can result in a corn or callus, it is often good to consider that they are not really a condition at all, but are a symptom of an underlying condition.
Corns and callus that are not treated will become painful. They will not come right on their own unless the pressure that caused them is taken away. If it is not the skin will continue to thicken and become more painful. After a while the body will start treating it as a foreign body and an ulcer (abscess) can develop. This can get infected - the infection can spread. Infection of corns on the toe is more common than a callus. This can be a serious complication for those with poor circulation, peripheral neuropathy and the need for diabetes foot care.
Corns and callus are easy to prevent - just take away the cause and that cause is excessive pressure. No chemical applied to the corn or callus will take away pressure. Correct fitting footwear around the toes, the use of pads to relieve pressure, surgical management of bony prominence and/or regular podiatric care are the best options for prevention of corns and callus.