Corns and Calluses

Corns and calluses are areas of thickened skin.

Corns usually develop between the toes or on the tops of the toes. Calluses usually develop on the bottoms (soles) of the feet, although they can form on the sides or on the toes. Corns and calluses are very common among older people. These conditions can be merely annoying at first but can become very painful. Some corns and calluses become inflamed and infected, especially in people with poor blood flow to the feet. Corns and calluses are often preventable. When they do form, however, they respond well to treatment.

Causes

Corns and calluses develop in response to friction or pressure. Friction occurs when skin rubs against skin (as often happens between adjacent toes) or when a sock or shoe rubs against a toe or another part of the foot. Pressure may occur when an ill-fitting shoe presses on the skin. Tight shoes and shoes that have a flat, hard toe box (the portion of the shoe where the toes fit) are especially likely to increase pressure on the skin. Also, fat and muscle tissue on the bottom of the feet thin with aging; thus pointy outgrowths of bone (spurs) and bumpy outgrowths of bone are more likely to press against the skin. When friction or pressure occurs regularly in the same area, a corn or callus forms gradually.

Symptoms and Diagnosis

A corn may be soft or hard. It is thickest at its center, or core. A callus is hard and is usually of equal thickness throughout. Some corns and calluses do not cause symptoms and can be merely annoying. However, most cause at least mild discomfort. Some cause enough pain to make walking difficult. Pain may worsen, and redness and warmth may develop if a corn or callus becomes inflamed and infected. Warts may resemble corns and calluses and may cause similar symptoms.

A doctor diagnoses a corn or callus by recognizing its typical appearance during a physical examination of the foot.

Prevention

Wearing properly fitting footwear is the best way to prevent corns and calluses. Shoes should be long enough and have enough space in the toe box so that there is no pressure on the tops of the toes. Finding footwear that fits properly is sometimes easier said than done. Spurs or bumpy outgrowths of bone can interfere with the fit and comfort of shoes. This discomfort can sometimes be lessened by affixing into the shoe a soft material, such as moleskin, lamb's wool, felt, or foam padding. If these measures are unsuccessful, an orthotist (a person skilled in the fitting of devices such as braces, splints, and inserts) can sometimes modify a shoe to reduce friction and pressure at certain points.

Treatment and Outlook

A doctor treats a corn or callus by using a scalpel to shave or pare away the thickened skin. Soft padding over the area is usually recommended to reduce pressure and protect the area where the corn or callus has been removed as well as to protect the surrounding healthy skin. The doctor may suggest adding a cream that softens thickened and hardened skin (emollient cream) to the padding. The doctor may also help the person modify his shoes to reduce pressure on the area where the corn or callus has been removed, refer the person to an orthotist, or recommend alternative footwear.

After a corn or callus has been removed, it will not likely recur if the person can find and continue to wear footwear that fits properly.

Self-treatment with the use of razor blades, knife blades, or nonprescription preparations of salicylic acid should not be attempted because of the risk of injury and infection. In addition, self-treatment rarely succeeds.