Corns and calluses

Corns and calluses are one of the most common conditions seen in a foot clinic. Basically, they’re really just the formation of hard and thickened areas of skin at places of excess pressure and friction - one of the body’s protection mechanisms. But while this protection mechanism often does just what it says on the tin – protect the body – it can also become problematic.

If the skin becomes too thick and hard, it can cause pain when walking or standing, or in any situation where excess pressure is applied.

What’s the difference between a corn and a callus?
First, let’s dispel a few common myths: corns aren’t contagious, and they don’t have roots.  Nor are they hereditary, genetic, or caused by ill-wishes or bad luck! In fact, corns (and calluses) simply form in response to pressure on the skin. Shoes that are too small, pinch, or squeeze the foot can cause a corn or callus to form.

However, although corns and calluses are physically the same, there are some structural differences. Corns are well-defined and cone shaped, with the point of the cone pointing down into the skin - in fact, it’s this central core of hard skin that distinguishes a corn from a callus, and what can make a corn very painful.  Also, corns tend to occur on bony parts of the feet, especially on the outside of the little toe and the top of the other toes. Calluses, on the other hand, don’t have this central core of hardened skin – they’re more dispersed and less well-defined than corns. Yellowish in colour, they normally form on the bony area of the sole of the foot, just beneath the toes, or on the heel. Although calluses aren’t generally very painful, they can hurt if the build-up is sufficient.

Are there different types of corn?
Yes, there are several types of corn, all with different characteristics and requiring different types of treatment.

  • ‘Soft’ corns – so-called because they feel soft compared to the more usual ‘hard’ corn. Soft corns occur between the toes and are kept soft by the moisture that tends to be found here. This type of corn is very painful.
  • Seed corns. These are very small and form on the sole of the foot.
  • Subungal corns, which form under the nail.
  • Neurovascular corns. This type of corn has nerves and blood vessels running through it, and can be relatively difficult to treat.

Treatments 
When considering treatment for corns and calluses, it’s worth remembering that they’re formed as a result of excessive friction and pressure – they’re not a disease, so although you should always look first for the underlying cause of the problem, it’s also reasonable to seek immediate symptomatic relief – particularly if the symptoms are pain! Common treatments include:

  • Excess skin removal . If you’re in pain, it’s wise to go to a local foot clinic and have the excess skin removed.
  • Salicylic acid. There are a number of over the counter products containing salicylic acid that can be used at home to remove excess skin. Although these products are safe, they should be avoided by those who have diabetes or poor circulation.
  • Padding. Several different types of pad are available from high-street pharmacies.
  • Shoe inserts. In some cases, the problem is biomechanical (the way that the foot functions during walking). In these instances, a more permanent shoe insert, known as an orthotic, may be required.
  • Subungal corns. These (corns underneath the nail) need professional attention.

As corns and calluses usually result from pressure or friction, they are quite easily treated by removal, followed by taking sensible measures to prevent recurrence. However, in some cases, such as if the problem results from deformation of the bones or joints of the foot, then corrective surgery may be required.

Prevention 
 Prevention of corns and calluses is pretty straightforward – it really just means avoiding things that cause excess pressure and rubbing on the feet. As shoes are, arguably, the single biggest cause of problems, getting properly-fitting footwear is essential, though some shoes can feel comfortable, but still causes some pressure or friction on certain parts of the foot. In such cases, it’s a good idea to consider investing in some foot padding in order to prevent the problem from escalating into a corn or callus. Keeping the amount of time that you wear high heels to a minimum is also a good idea.