Corns and calluses: what causes them and when to see a chiropodist

Corns and calluses are among the most common things we see, and among the most commonly misunderstood. They are not a disease and they are not a sign of poor hygiene. They are your skin doing exactly what it is supposed to do, which is thicken where it is being pressed or rubbed repeatedly.

That is worth knowing, because it explains why they come back. Remove the hard skin and leave the pressure in place and the skin will simply build up again, usually within a few weeks.

The difference between the two

A callus is a broad area of thickened skin, most often on the sole of the foot, around the heel or across the ball of the foot. It is usually not painful, though it can feel uncomfortable or burning if it becomes very thick.

A corn is smaller and more concentrated, with a firm centre, and forms on the tops or sides of the toes or on the parts of the sole that take the most weight. Corns are far more likely to hurt, because that firm centre presses down into more sensitive tissue underneath. People often describe the feeling as standing on a small stone.

Why they form where they do

Something is loading that spot more than the rest of the foot. Shoes that are too tight, too loose or the wrong shape are the usual explanation. Long hours standing will do it. So will the way you walk, if it puts more pressure through one part of the foot than another.

A bunion or a toe that sits in a claw or hammer position changes where the pressure goes, and corns very often form on exactly those prominences. Thinning of the natural fat padding under the ball of the foot, which happens with age, is another common reason.

What not to do

Corn plasters containing salicylic acid are widely sold and are not suitable for everybody. They work by breaking down skin, and they do not distinguish very well between hard skin and healthy skin around it. They are best avoided if you have diabetes, poor circulation or reduced feeling in your feet.

Cutting at a corn yourself with a blade is a reliable way to end up with an infection. Filing gently with a foot file after a bath, and moisturising, is the sensible home approach for a callus.

When to get them treated

It is worth seeing a chiropodist if the area is painful, if it keeps returning, if there is any sign of infection such as redness, heat or discharge, or if the corn is between the toes, where the skin stays damp and breaks down more easily.

If you have diabetes, circulatory problems or reduced sensation in your feet, do not treat them yourself at all. Have them looked after professionally. Small problems in a foot with poor circulation or reduced feeling can become serious ones, and this is the group for whom regular professional foot care makes the biggest difference.

What treatment involves

A chiropodist will reduce the hard skin safely, which is usually immediately comfortable, and will remove the centre of a corn where there is one. That part is not painful.

The more important half of the appointment is working out why it formed. That means looking at your footwear, at the shape of your foot, and at how you load it when you walk. Where the cause is mechanical, padding, a change of shoe or an insole can take the pressure off the spot, which is the only thing that stops the problem returning.

Where the pattern suggests something further up, a biomechanical assessment or custom orthotics may be the answer rather than repeated treatment of the skin.

A note on the words

Chiropody and podiatry are the same profession with the same training. In practice, chiropody tends to describe the skin and nail care side of the work, and podiatry the assessment of how the foot functions. At our Haslemere clinic both sit in the same team, which means the skin can be treated and the cause investigated in the same place.