Corns and Calluses: causes, symptoms and treatment

What's the Difference Between a Corn and a Callus?

A corn usually forms on the top of the foot and/or toes, over a joint or bone. The core of the corn is the dense, thick knot at the very center, which forms over the point of the greatest compression or friction from your shoe. Corns can cause discomfort and make it harder to walk or run in your shoes.

Corns can be soft or hard: soft corns are supple and tender and are usually found on the delicate skin between the toes. They are kept moist by sweat and are prone to infection. Hard corns are firmer and drier and form on the knobby toe knuckles and outer edges. Most people develop corns due to wearing shoes that are too tight.

A callus develops in response to excessive rubbing and friction. It looks like a dull yellow, flat, rough layer of skin and is usually found on the sole of the foot. Unlike a corn, a callus has a uniform thickness. Calluses can sometimes be painful or make walking more difficult.

Most calluses form when the foot isn’t fitting well in the shoe, and there is space for parts of the foot to move around and rub against the inside of the shoe. In some cases, a callus may form due to problems with walking. A change in your gait might change the way your foot slides around in your shoe, creating a new area of friction where a callus might develop.

Diagnosing Corns and Calluses

When you make an appointment with your foot and ankle specialist about corns or calluses, make sure to bring your shoes. Your doctor will want to examine how your shoes fit to understand how they are rubbing or causing excessive pressure in certain areas of your foot.

Your doctor will also be on the lookout for foot abnormalities that may be impacting your foot’s mechanics. This may include:

• Mal-aligned bones

• Structural deficiencies in the bones

• Toe deformities

• Any abnormal walking patterns (such as pigeon-toeing)

Plantar Keratosis

Plantar keratosis is a deep callus that causes extreme amounts of discomfort. The painful lesion is a collection of dead skin cells that harden over time. They take place on the bottom of the foot and can feel like you are walking with a pebble in your shoe.

Some can confuse plantar keratosis with a wart or even think there is a problem with the underlying bone because these lesions can be so painful. The natural fat pad on the bottom of the foot thins with age which can cause you to be more susceptible to these kinds of skin calluses.

Types of Corns

Hard Corns

A hard corn is the most common type of corn and is characterized by a small area of dense skin surrounded by thickened and inflamed red skin. They are often caused by friction from shoes and usually occur on the top of the toes.

Soft Corns

Soft corns often develop as a result of friction between the toes. This can be caused by a toe bone that is too wide or wearing high-heels with a narrow toe box. Moist skin (as a result of sweat or poor drying of the feet) between the toes can be another cause of soft corns.

Seed Corns

Seed corns often develop on the bottom of the feet as a result of standing or walking on a hard surface for extended periods of time. Ill-fitting shoes or socks can also lead to seed corns. These hard, seed-like bumps and can present as a single corn or a cluster of tiny corns.

Fibrous Corns

When a corn has been present for a long time they begin to attach to deeper tissue. The result is fibrous corns, which can be very painful.

Vascular Corns

Vascular corns have blood vessels within the corn and can bleed heavily if cut or scraped. They are often painful.

Lister Corns

Lister corns develop on the inside and outside of the nail bed, usually on the 5th toe. Some patients describe a Lister corn as having a second toenail on the toe. 

Treating Corns and Calluses

Corns and calluses can be treated conservatively at home or with the help of a podiatrist. The most effective treatments usually involve redistributing the pressure on your foot to help you move more normally and comfortably in your shoes.

Wear Better Fitting Shoes

Your shoes should have plenty of room in the toe box to cut down on the pressure on your toe joints. Usually, this helps shrink the corn or callus within a few weeks or months.

Use Moleskin

Moleskin is inexpensive and can be found at most pharmacies. Moleskin can cushion the sore and cut down on the direct friction to your skin. For corns, you can try cutting a “doughnut” shape out of moleskin, foam, or felt to relieve the pressure on the core.

Wear Orthotics

An orthotic is designed to augment the fit of your shoe and redistribute your weight to alleviate excessive pressure. Your foot and ankle specialist can fit you for a custom set.

Keeping the Corn or Callus Trimmed

Your foot and ankle specialist can shave down the thick layers using a scalpel blade. This can reduce the pain you feel while wearing your shoes by reducing the pressure on your foot. The corn or callus may return later, requiring additional treatment. However, if you wear the right shoes or start using well-fitting orthotics, the corn or callus usually won’t return.

Surgery

This option is usually only recommended for severe cases, or when your foot has a structural deformity that is causing persistent problems. The focus will be on improving overall foot mechanics to prevent excessive pressure and friction during your normal activities.

What happens if my corn or callus gets infected?

While complications of corns and calluses are rare, infections and ulcers can occur. In such cases, the corn or callus would become more painful and the surrounding skin would be red and sore. If this happens, you should see your podiatrist or wound care specialist as soon as possible. You may be prescribed antibiotics and in some cases, the damaged tissue will need to be removed. 

Because diabetics are particularly prone to infections and ulcers, they should regularly examine their feet to identify any problems right away.