Corns, callosities, and calluses

Corns, callosities, and calluses are areas where the skin has thickened and hardened as a result of friction or pressure.

Corns are generally small and round in shape. They appear on the sides, tops, and tips of the toes and on the soles of the feet. The centre of a corn is hard and painful when pressed. When corns develop between the toes (usually between the 4th and 5th toes) they're referred to as "soft corns." Because of the moisture caused by perspiration in this area, soft corns have a whitish appearance.

Callosities are a thickening on the skin's surface that is spread over a larger area than a corn or callus. They appear on the sides or sole of the foot and on the heel, and are generally not painful. If there is excessive rubbing in the area, you may experience a burning sensation.

Calluses tend to be more localized and rigid than callosities. Although it can be difficult to tell the two apart, the outline of a callus is less distinct than that of a corn. They are often located on the sole of the foot, particularly near the front, or on the palm of the hand, in areas that experience pressure or friction.

Causes and triggers

These skin issues are caused by pressure and friction due to the following:

• Ill-fitting shoes
• Wearing shoes without socks
• Walking barefoot
• Weight gain
• An unbalanced gait when walking
• A bony protuberance:
  • A bunion (joint deformity at the base of the big toe)
  • A hammer toe (raised middle joint)

Calluses appear on the hands when tools or instruments are used without gloves. For instance, hand calluses may develop after using a shovel and are fairly common among guitar players.

Inflammation and infection can develop in corns and calluses. It is also important to differentiate these issues from plantar warts. You can tell them apart by looking at the grooves in the skin, which follow the contour of a plantar wart, but run straight through a corn or callus.

Treatment

There are several ways to prevent the formation of corns, callosities, and calluses:

• Avoid walking barefoot.
• Use padding to prevent rubbing or to distribute support evenly across the foot.
• Wear socks with your shoes.
• Wear well-fitting shoes:
  • Approximately a 1.25 cm gap between the longest toe and the front edge of the shoe
  • Closure mechanism to keep the foot from sliding around inside the shoe
  • Light, flexible, and breathable
  • Not too narrow
  • Provides good arch support
  • No high heels

For corns, callosities, and calluses that have already formed, it is important to reduce pressure and rubbing in the affected area.

• Remove any excess skin:
  • Soften the affected area by soaking for around 10 minutes in lukewarm water.
  • Remove excess skin with a file or pumice stone only, do not cut away the skin.
  • Apply a salicylic acid treatment if necessary:
    • Leave the dressing in place for around 48 hours, remove any remaining excess skin, and repeat if necessary.
    • Be sure to protect healthy skin with a bandage that has an opening or by applying petroleum jelly.
    • Discontinue use as soon as the area is healed, or after 2 weeks of use.
• Protect the affected areas:
  • Use corn pads with holes to cushion the tender area.
  • Use separators between the toes for soft corns.
  • Add padding to the affected areas or wear cushioned insoles.

People with diabetes or poor circulation in their legs should consult their health care provider before self-treating.

When should I see a health care professional?

Consult your health care provider in the following cases:

• There is no improvement after 2 weeks of treatment
• There are signs of infection such as inflammation, redness, increased pain, or fluid leaking from the affected area
• You have a corn, callosity, or callus and you are diabetic or have poor circulation in your legs