Home > Foot Problems > Corns
| * Explanation | * Symptoms | * Diagnosis | * Duration |
| * Prevention | * Treatment | * Call your Doctor | * Prognosis |
Corns and calluses are both forms of hyperkeratosis — a protective thickening of the outer layer of skin. They develop as part of the skin's normal defense against prolonged rubbing, pressure and other forms of local irritation.
Corns — A corn, medically known as a heloma or clavus, is a protective thickening of the skin on a bony, knobby portion of a toe. At the center of a corn is often a very dense knot of skin called a core, which is located over the area of greatest friction or pressure.
Firm, dry corns that form on the upper surfaces of the toes are sometimes called hard corns, whereas pliable, moist corns that form between the toes are called soft corns. In most cases, corns develop when the foot has been squeezed into a shoe that has a very narrow toe box. Less often, corns develop on deformed toes that cannot fit comfortably into regular shoes.
Calluses — A callus, also known as a tyloma or tylosis, is a protective thickening of skin that is exposed to prolonged rubbing. Unlike a corn, a callus is a uniform thickening; there is no dense, central core. Although calluses most commonly occur on the soles of the feet, they can occur on other parts of the body that are exposed to long-term friction. For this reason, calluses are often found on the hands of manual laborers, guitar players, gymnasts, weight-lifters, tennis players and other individuals who routinely handle tools, instruments or sports equipment. In laborers and athletes, calluses may actually be a physical advantage, because they cushion the hands and allow the individual to work or compete without pain.
On the soles of the feet, calluses typically develop near the bases of the toes, where they are usually caused by friction from poorly fitting shoes. Less often, calluses are related to gait problems or foot abnormalities that place unusual stress on parts of the foot during walking. According to statistics from the American Podiatric Medical Association, painful corns and calluses affect about 5 percent of the U.S population every year. Unfortunately, statistics also show that many individuals never seek professional help.
On the feet, a small corn or callus may be asymptomatic (produce no symptoms). However, a large, bulky corn or callus can cause foot pain and difficulty walking.
After prolonged irritation, a discoloured area (brown, red, black) may sometimes develop under a large corn or callus. This discolouration is caused by small hemorrhages (bleeding) in the margin between thick and normal skin. In severe cases, a cleavage plane may actually form between the thick and normal skin, exposing the area to possible infection, especially in persons with diabetes.
What Your Doctor Looks For
Your doctor will probably ask questions about your shoes, because shoes with narrow toes are more likely to cause corns. He or she will also ask about your foot history. Some types of foot problems can alter the mechanics of the foot, producing abnormal pressure on certain areas and leading to callus formation. Also, any previous surgery or trauma to the feet may affect the structure and alignment of foot bones, increasing the risk of calluses.
In most cases, your doctor can diagnose corns and calluses by examining the affected area of your foot. The next step is to determine why these problems have occurred — are they being caused by poorly fitting shoes or by underlying foot abnormalities?
To assess whether your corns and calluses are related to foot abnormalities, your doctor will inspect your feet for toe deformities, structural abnormalities of the bones, poor bone alignment and problems related to abnormal gait. If your doctor finds some abnormality during this part of the foot exam, he or she may suggest a specific type of padding or shoe insert that will help prevent your corns and calluses from recurring.
Also, whenever there is a painful area of thickened skin on your feet, your doctor may need to rule out a plantar wart (a localized skin infection caused by human papillomavirus).
Corns and calluses may be a long-term problem if you consistently wear shoes that do not fit properly. Even with good footwear, you may continue to suffer from painful corns and calluses if there is some underlying abnormality in your gait or foot structure that causes unusual stress on parts of your feet when you walk.
In most cases, you can decrease your risk of corns and calluses by wearing shoes that fit properly. In particular, choose low-heeled, comfortable shoes that have ample space around the toes. Wear socks to cushion any areas of unusual rubbing or pressure, and use foot powder to reduce friction.
If you suffer from painful corns and calluses, your doctor will usually trim away some of the thickened skin to relieve pain and pressure in the affected area. Your doctor may also recommend that you use specific footwear modifications to prevent your problem from returning: For example, pads or "donuts" made of moleskin, lamb's wool, foam or felt will cushion the affected area. And corrective shoe inserts will redistribute the forces that cause friction and pressure inside your shoes, relieving some of the stress on your feet when you walk.
At the end of your office visit, the doctor may ask you to return on a regular basis to have your feet examined and your corns and calluses shaved (if necessary).
You can also minimise corns and calluses by regularly rubbing them with a pumice stone (available in most drug stores).
In very rare cases, foot surgery may be necessary to treat recurrent corns and calluses that are not relieved by padding, shoe inserts and periodic shaving. Most often, this type of surgery is performed to correct an underlying abnormality of bone structure in the foot.
Important: Never try to shave or cut a corn or callus on your own. Instead, use a pumice stone to trim it down safely. Also, you can use nonprescription medications to "dissolve" away corns and calluses. However, persons with diabetes or poor circulation should avoid these products.
Make an appointment to see your family doctor, orthopaedic surgeon or podiatrist if you have painful corns or calluses.
If you are a diabetic, or if you suffer from poor circulation, examine your feet every day. For the best view, use a mirror to inspect the soles of your feet and the skin folds between your toes. If you see an area of redness, swelling, bleeding, blisters or any other abnormality, call your doctor promptly.
Although corns and calluses tend to recur, this may not happen right away if you follow your doctor's instructions for foot padding, shoe inserts and proper foot hygiene.