What is a corn? What is a callus?

Corns and calluses are hard, thickened areas of skin that form as a consequence of rubbing, friction or pressure on the skin.

Corns and calluses form on the feet and can make walking painful.

Although corns and calluses are often talked about together, they are separate conditions.

Corns generally occur on the tops and sides of the toes. A hard corn is a small patch of thickened, dead skin with a small plug of skin in the centre. A soft corn has a much thinner surface, appears whitish and rubbery, and usually occurs between the toes. Seed corns are clusters of tiny corns that can be very tender if they are on a weight-bearing part of the foot. Seed corns tend to occur on the bottom of the feet, and some doctors believe this condition is caused by blocked sweat ducts.

Calluses are hard and rough-feeling areas of skin that can develop on hands, feet or anywhere there is repeated friction – even on a violinist’s chin. Like corns, calluses have several variants. The common callus usually occurs when there has been a lot of rubbing against the hands or feet. A plantar callus is found on the bottom of the foot.

What causes corns and calluses?

Some corns and calluses on the feet develop from an improper walking motion, but most are caused by ill-fitting shoes. High-heeled shoes are the worst offenders. They put pressure on the toes and make women four times as likely as men to have foot problems. Other risk factors for developing a corn or callus include foot deformities and wearing shoes or sandals without socks, which leads to friction on the feet.

Rubbing or pressure can cause either soft corns or plantar calluses. If you or yourchild develops a callus that has no clear source of pressure, have it looked at by a doctor or a podiatrist, since it could be a wart or be caused by a foreign body – such as a splinter – trapped under the skin. Feet spend most of their time in a closed, moist environment, which is ideal for breeding fungal and bacterial infections. Staph (bacterial) infections can start when bacteria enter corns through breaks in the skin and cause the infected skin to discharge fluid or pus.

What are the symptoms of corns and calluses?

• A callus is a patch of compact, dead skin anywhere on the body that is subject to friction. There are different common names given to various types of calluses.
• A hard corn is a compact patch of hard skin with a dense core, located on top of a toe or the outside of the little toe.
• A soft corn is a reddened, tender area of skin, has a thin, smooth centre and is found between toes.
• A seed corn is a plug-like circle of dead skin, often painful, on the heel or ball of the foot.
• A plantar callus is a callus on the bottom – or plantar – surface of the foot.

How do I know if I have a corn or a wart?

To find out whether a hard patch of skin is a corn or a wart, your doctor will examine the affected area. Warts are viral and often have black dots present in the affected skin. They also require specific treatment. Most calluses are corrected by a variety of measures, including a change in shoes, trimming of the calluses and sometimes surgery.

What are the treatments for corns and calluses?

Most corns and calluses gradually disappear when the friction or pressure stops, although your doctor may shave the top of a callus to reduce the thickness. Properly positioned moleskin pads can help relieve pressure on a corn. There are also special corn and callus removal liquids and plasters, usually containingsalicylic acid, but these are not suitable for everyone.

Oral antibiotics generally clear up infected corns, but pus may have to be drained through a small incision.

Moisturising creams may help soften the skin and remove cracked calluses. Apply the moisturising cream to the callus, and cover the area for 30-60 minutes with a plastic bag or a sock – but only if instructed to do so by your doctor or podiatrist.

Then gently rub off as much of the callus as you can with a coarse towel or soft brush. Using a pumice stone first to rub off the dead skin from a callus after a bath or shower and then applying moisturising cream can also be effective.

There are also stronger creams containing urea that might be more effective, but do not use these unless recommended by your doctor or podiatrist. Do not usehydrocortisone creams, which only help with rashes and itching and are not needed for calluses. Moisturising your skin incorrectly can aggravate a fungal condition and should be avoided – especially moisturising between the toes.

You may consider surgery to remove a plantar callus, but there are no guarantees that the callus will not come back. A conservative approach is best initially. Keep your feet dry and friction-free. Wear properly fitted shoes and cotton socks, rather than wool or synthetic fibres that might irritate the skin.

If a podiatrist (a foot specialist) or orthopaedic specialist (a bone and jointspecialist) thinks your corn or callus is caused by abnormal foot structure, your walking motion or hip rotation, orthopaedic shoe inserts or surgery to correct foot deformities may help correct the problem.

How can I prevent corns and calluses?

• To avoid corns and calluses on the feet, always have both feet professionally measured when buying shoes, and only wear properly fitting shoes.
• Make sure that both shoe width and length are correct – for each foot – since your feet may be slightly different sizes. Allow up to 1.3cm (half an inch) between your longest toe and the front of the shoe. If you can’t wiggle your toes in your shoes, they are too tight.
• Avoid shoes with sharply pointed toes and high heels. Women who prefer such shoes, or who are expected to wear them at work, can take some of the pressure off their feet by walking to their destination in well-fitted flat shoes, and then changing them. Try to decrease heel height as much as possible.
• Have your shoes repaired regularly – or replace them. Worn soles give little protection from the shock of walking on hard surfaces, and worn linings can chafe your skin and harbour bacteria.
• Worn heels increase any uneven pressure on your heel bone. If the soles or heels of your shoes tend to wear unevenly, talk to you doctor about corrective shoes or insoles.
• If you have hammertoes – toes that are buckled under – make sure that the shape of your shoes offers plenty of room to accommodate the buckled toes.