Corns and calluses are annoying and potentially painful thickenings that form in the skin in areas of excessive pressure. The medical term for the thickened skin that forms corns and calluses is HYPERKERATOSIS. A callus refers to a more diffuse, flattened area of a thick skin, while a corn is a thick, localized area that usually has a popular, conical or circular shape. Corns, also known as HELOMAS or CLAVI, sometimes have a dry, waxy, or translucent appearance. A callus is also known as TYLOMA.
Corns and calluses occur on parts of the feet and sometimes the fingers. Corns are often painful, even when they are small. Common locations of corns are:
- On the bottom of the foot (sole), over the ball of the foot.
- On the outside of the fifth (small or pinky) toe, where it rubs against the shoe.
- Between the fourth and fifth toes. Unlike other corns that are firm and flesh coloured, corns between the toes are often whitish and messy; they are sometimes called SOFT CORNS. In contrast to the more common hard corns found in other locations.
The thickening of the skin occurs as a natural defence mechanism that strengthens the skin in areas of friction or excessive pressure. Abnormal anatomy of the feet, such as hammertoe or other toe deformities, can lead to corn or callus formation as can bony prominences in the feet. Footwear that is too tight or exerts friction at some specific points can also cause skin thickening that leads to corns and calluses. Abnormalities in gait or movement that results in increased pressure to specific areas can also be the cause.
It can be hard to know why finger corns develop since they often don’t appear at sites of obvious pressure. Finger calluses may appear or develop in response to using tools, playing musical instruments such as the guitar, or using work equipment that exerts pressure at specific sites.
In many situations, calluses and corns can be prevented by reducing or eliminating the circumstances that lead to increased pressure at specific points on the hands and feet. Potential preventive measures therefore include the following:
- Wearing well-fitting comfortable shoes is useful. The idea is to avoid having footgear press on the outside of the fifth toe or pressing the fourth and fifth toes together to prevent corns in these areas.
- Another approach is to pad the potentially affected area. Many sorts of padding are available at the drug store.
- Cushions to put between the toes.
- Foam or moleskin pads to put over the places where the corns form.
- Foam pads with holes in the centre, which redistribute pressure around the corn instead of right over it.
- Cushioned insoles to pad the feet and alleviate mechanical pressure.
SIGNS AND SYMPTOMS
- Hardened, thick areas of skin
- Rounded or conical and may appear as a bump on the skin
- Dry, scaly or flaky
- Painful if they interfere with walking or other activity. Calluses are typically painless.
Corns and calluses can be treated with many types of medicated products to chemically pare down the thickened, dead skin. Many products are available for use as home remedies. These products all share the same active ingredient- SALICYLIC ACID.
Salicylic acid is a keratolytic, which means it dissolves in protein, which makes up most of both the corn and thick layer of dead skin which often tops it. Used as indicated on the package directions, these products are gentle and safe for most people. Salicylic acid treatments are available in different forms including:
All of these treatments will turn the top of the skin white and allow the dead tissue to be trimmed or peeled away, making the corn protrude and hurt less.
It is generally recommended that salicylic acid shouldn’t be used by diabetic patients, or when there is frail skin or poor circulation (because of concern about how the skin can heal). In these situations, application of salicylic acid can potentially lead to ulcer formation on the skin. A doctor can help determine whether salicylic acid-based products are safe for use on a particular individual.
Do not attempt to cut or shave away corns and calluses at home. This can lead to potentially dangerous infection of the surrounding tissues. This should be performed by a podiatrist. Antibiotics may also be prescribed for corns and calluses that have become infected.