FOOT CORN: THE WHAT(S) AND WHY(S)
What is a corn?
A foot corn is an area of thickened skin that can often be confused with warts and calluses. It is a compact area of dead thickened skin that is formed on a particular site of the body, mainly the foot, due to sustained increased friction or pressure in this area over a long period of time.
How foot corn is formed?
A foot corn is formed due to repeated sustained pressure or friction at a particular site on the feet. Due to this, the skin at that area becomes thickened and hard to compensate for the extra load that it has to withstand.
The skin forms a barrier protecting the inner soft tissues and organs from the direct exposure to the environment. But when this barrier begins to be abused, then the body tries to adapt to this in order to function more efficiently. Thus the resultant corn or callus is formed.
In a hard corn or seed corn, the inner core is hard. Whereas in a soft corn which forms mainly in the space between adjacent toes, the increased amount of sweat in this area continuously dampens and thus softens the core, thus the corn as a whole is soft.
Why does a corn form?
The friction and the sustained pressure that leads to the formation of a corn can arise due to a variety of reasons. They are :
- Ill-fitting shoes.
- Abnormality in the anatomy of feet
How does a corn look like?
- A compact hard yellowish lump on the skin with a hard inner core.
- Pain on touching/applying force or tenderness
- Pain during the activity that has caused the callus to form (Eg: wearing shoes).
Types of corn :
A corn can have varied presentations. These are classified into types as :
- Hard corn: A compact hard lump on the skin that mainly forms on top of a toe or the upper outer surface of the fifth toe.
- Soft corn: A soft lump of skin similar in other presentations to a callus. Mainly found in the space between two toes.
- Seed corn: A hard compact seed like circle of dead skin that mainly is found on the bottom of the foot, most often on the ball of the foot at the base of the toes or the heel.
Difference between corn and callus
We often confuse between a corn and a callus because they both present in a similar fashion. And also they have the same type of trigger that is acting to bring them into existence. A constant friction or pressure.
So how do we differentiate between a corn and a callus? Just by looking at it and its feel….
A callus is an area of thickened skin that occurs over a diffuse or large area and the limits or borders are not very distinct. Since it is more diffuse and spread over a larger area, there won’t necessarily be much pain as compared to a corn on applying pressure in that area.
On the other hand, a corn has a central core or plug and is much more localized and painful compared to callus. This pain because of its localized nature of development.
Corn or wart?
Corns and warts are two completely different entities. They differ in their numbers, locations, and presentation.
A wart is more likely to occur on the undersurface of the foot. They mainly occur due to walking barefoot which can predispose to infections in these areas, resulting in the formation of warts. Warts will have a crusted appearance and can have black dots in them. They usually occur in multiple numbers. And most importantly, warts are contagious. This is because they are caused by a virus called the Human Papilloma virus (HPV).
A corn, on the other hand, is more likely to occur at places where there is a prominence (even the heel or ball of foot) due to which there is a resultant increase in pressure and friction in these areas. Having a central hard core the corn presses on the nerves when pressure is applied and can cause pain. A compact area of dead thickened skin, yellowish in color and usually is single in number. But is a corn contagious? No, they are not contagious.