What are Corns and Calluses?
The human foot is an incredible structure. One of its special properties is that the skin on the bottom is many times thicker than elsewhere on the body. And, when exposed to certain conditions, this skin can increase its growth rate to protect itself. If your leg was subjected to the same abuse as your feet it would break open as a wound, because its lacks this protective ability.
Both a corn and callus are the result of increased growth of the skin cells which make the skin thicker. As the skin matures the outer layer dies and hardens. This accelerated growth results from abnormal pressure or shearing forces (rubbing). The mechanism is the same for both a corn and a callus. The difference is that a corn is a circumscribed area of increased tissue growth usually due to a boney prominence. This small circular area grows faster than a callus caused simply rubbing. And, it develops into a “rock like” lump of hard, dead skin. This sets up a vicious cycle: the thicker and deeper the “rock” becomes, the more pressure is put on the underlying growing cells – which, in turn, grow faster, causing more dead, hard tissues.
Usually calluses form on the bottom of the foot. When they form it is the result of structural weaknesses leading to abnormal motions and friction. This type of problem can be addressed by improving the biomechanics of walking. Prescription Orthotics, which act like an orthodontic “bite plate” can help align foot structure and improve function. When the foot is functioning normally, it won’t develop calluses.
Corns can also form on the bottom of the foot if certain bones “drop” and become more prominent. This causes more pressure in a small area. Usually corns form on the toes. The most common cause is increased pressure on the joints from confining foot wear. “Stylish” women’s shoes tend to be fitted tighter, since they usually hold on to the foot by only touching the toes. Shoe with laces or straps over the instep will allow the part over the toes to be looser and not cause excess pressure.
People of all ages can develop corns and calluses – but it is most common among those 65 years of age or older.
Myth: “Paring or filling the dead tissues makes the corn or callus grow faster”. In fact, removing the dead tissue reduces the pressure on the growing layer of the skin, thus slowing its growth.
- Reduce the build-up of thick skin by having a Podiatrist safely remove it. This will reduce pressure on the growing layers of skin and allow the growth rate to return to normal.
- Assess foot wear. Make modifications where possible to limit pressure on boney prominences.
- If there are structurally abnormal bone shapes or positions which cause a prominent are that gets too much pressure, help is at hand. Surgical procedures to reduce these deformities can be performed in a Podiatrist’s office. This is done under local anesthetic just as Dental surgery is. Patients remain mobile and walk out wearing only a temporary “Surgical Slipper”.
Corns and calluses are not normal. Not only are they painful; they tell you that something is wrong. Do not ignore them! Help is available at your Podiatrist’s office.
May is foot health month. Don’t ignore your tootsies! For the podiatrist nearest you: www.opma.ca