A corn is a focal area of thickened skin that forms as a result of pressure, friction or rubbing. Typically, they are found over prominences of the foot e.g. on the top of hammer toes (caused by rubbing from footwear), over a bunion, or on sole of the foot (usually caused by focal pressure over a bony joint related to your gait pattern/how you walk and footwear).
Corns cause pain and reduced mobility, and if left untreated or treated incorrectly (see below) can become infected or ulcerated.
Corns can be serious if you have a loss of feeling in your feet such as in diabetes. You should consult a podiatrist urgently if this is the case.
This GARGANTUAN corn was complicated by repeated use of corn plasters.
Image used by kind permission of my patient.
There are 3 types of corns: -
Hard Corns – ‘Heloma Durum’; the most common and found in the locations described above.
Soft Corns – ‘Heloma Molle’; these are arguably the most uncomfortable/downright painful – and more tricky to treat because of this.
Seed Corns – ‘Heloma Millare’; these are atypical as they can form in places where there is no pressure e.g. the arch of the foot. They may or may not cause pain, in my experience. Their aetiology (cause) is not well known.
Please, PLEASE, do NOT use corn plasters. Corn plasters contain Salicylic Acid. This will soften the skin and, in theory, the corn, and allow the corn to be ejected from the skin when the plaster is peeled off. The reality is that Salicylic Acid is not specific for just the ‘corny’ skin; it will damage/burn the healthy skin surrounding the corn causing a right old mess. In my experience, it also makes effective removal of the corn more difficult as the skin is now soft (macerated) and actually it’s a lot easier to remove the corn when the skin is dry and the corn is hard.
Corns need to be enucleated (removed using a scalpel) by a podiatrist.
They may or may not come back. Typically they will return unless the cause of the pressure/friction/rubbing is removed. BUT there is also a ‘memory theory’ relating to the skin… whereby even if the cause of friction is removed, and the corn is enucleated fully, it will still return as the skin ‘remembers’ the corn having been there and it forms again, almost like a scar tissue. (I will add the paper on this when I find it…)
Application of an urea-containing emollient can help to soften the corn to ease the pain and slow reoccurrence.
A podiatrist can also provide devices to offload/prevent friction e.g. between toes, or orthoses to redistribute the pressure across the soles of your feet to slow down or prevent the reoccurrence of the corn.
FOOTWEAR. Draw around your foot on a piece of plain paper. Place your shoe on top of the drawing; does your foot fit within the borders of the shoe? Look at the profile of your foot. Hammer or clawed toes? Do these fit adequately in the toe box of your shoe? No? Your footwear must accommodate the size and shape of your feet to prevent rubbing. It’s not rocket science, kids.
There are some surgical options available for recalcitrant cases where the pain is affecting your quality of life. These procedures will be performed by a Podiatric or Foot & Ankle Surgeon or a Consultant Dermatologist, depending on the procedure.
HOW CAN I TELL WHETHER IT'S A CORN OR A VERRUCA?
A corn has a hard, flat surface. A verruca has a ‘cauliflower’ surface
A corn is painful on direct pressure. A verruca is painful if it is squeezed.
A corn does not contain any ‘black dots’ (capillaries). A verruca contains capillaries.
A corn is a focal area of hard skin. A verruca is a wart caused by a strain of the human papilloma virus.
A corn is easy to treat. A verruca is not.
For more information, please get in touch.