What is Callus?

A callus also called a callosity, is an area of thickened skin that is formed due to repeated friction, pressure or irritation to a particular part. It is similar to a corn except that it is flat and slightly larger while a corn is usually smaller and has a hard central core. A corn tends to be painful while a callus may or may not be painful. While a callus is usually formed on the undersurface of the foot, a corn can be formed on the top of the toes or even between the toes.

The word callus is also used for bone growth that occurs following a fracture. However, this article will be exclusively regarding callus formation of the skin.

What are the Causes of Callus?

A callus occurs at any site exposed to repeated friction. The repeated friction causes increased multiplication of skin cells called keratinocytes, which accumulate resulting in thickening of the skin. They also form under a bony prominence due to repeated pressure to the part. The multiplication of skin cells is actually a protective mechanism to prevent the skin from getting peeled off.

Calluses are commonly caused by wearing shoes that do not fit well or by not using footwear. Excessive pressure caused at a particular point due to a foot deformity like hammertoe also stimulates callus formation.

In some cases, a callus may be due to an underlying cause. For example, nerve damage caused by conditions like diabetes could result in uneven distribution of weight on the foot and predispose to callus formation at pressure points.

What are the Symptoms of Callus?

A callus is commonly found on the foot where a prominent part of the bone presses against the footwear. Thus, calluses are found on the lower surface of the foot, inner side of the great toe, over the balls of the foot, and at the margins of the heels. On examination, they are usually:

  • Lighter than the normal skin color, though the color may vary
  • Firm to feel
  • Pain may or may not be present
  • The surface may show scaling or flaking
  • The thickened tissues fail to get adequate blood supply and the callus may break down with cracks on the surface or into a skin ulcer.
  • Bacteria may enter the wound and result in an infection. Infections especially in diabetes patients are difficult to treat.
  • The patient may walk with a limp due to the pain

How to Diagnose Callus?

Callus is diagnosed based on physical examination of the patient. The presence of a callus may indicate an underlying condition like a neuropathy, which should be ruled out.

How do you Treat Callus?

A callus should be treated to prevent complications like ulceration and infection. Any infection should be addressed with antibiotics. Patients with diabetes should ensure that their blood glucose level is under control.

The size of the callus can be mechanically reduced by using a buffing pad or by paring it down. This should be done by a podiatrist and should not be done at home to avoid further damage.

Several over-the-counter products are available for the treatment of callus, which help to thin out the callus. Patients with diabetes should not use these products.

Pads can be used between the shoes and the callus to prevent friction and pain.

Special custom-made shoes or shoe inserts can be used to redistribute the weight from the pressure areas.

Surgical treatment may be necessary to correct any minor deformity, and prevent repeated callus formation.

Health Tips

Shoes should be well-fitting and not cause any shoe bites. They should support the foot well and not result in excessive pressure over any points.

Regular foot care is a must. Thickened skin may be rubbed with a pumice stone after soaking in water.

If you suffer from diabetes, get your feet checked by a physician on a regular basis.


  1. Sussman C, Bates-Jensen BM. Wound Care: A Collaborative Practical Manual for Health Professionals 3rd edition.
  2. Watkins PJ, Amiel SA, Howell SA, Turner E. Diabetes and its Management. 6th edition.
  3. Frowen P, O’Donnell M, Lorimer D, Burrow G. Neale’s Disorders of the Foot: Clinical Companion.

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