Corns and calluses are annoying and sometimes painful thickenings in the skin in areas of repeated pressure.
Symptoms and signs of corns and calluses include
a thick, hard patch of skin;
bump on the skin;
area of flaky, dry skin;
pain or tenderness of the affected area.
Corns and calluses can be treated with many types of medicated products to chemically pare down the thickened, dead skin.
Salicylic acid is the ingredient used in most corn and callus removal products.
Corns and calluses can be prevented by reducing or eliminating the circumstances that lead to increased pressure at specific points on the hands and feet.
People with fragile skin or poor circulation in the feet (including many people with diabetes or peripheral arterial disease) should consult their health-care professional as soon as corns or calluses develop.
What are corns and calluses?
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 ishyperkeratosis (plural=hyperkeratoses). A callus refers to a more diffuse, flattened area of 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 a 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 for corns are
- on the bottom of the foot (sole), over the metatarsal arch (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-colored, corns between the toes are often whitish and messy; this is sometimes called a “soft corn” (heloma molle), in contrast to the more common “hard corn”
What causes corns and calluses to develop?
Hyperkeratosis simply means thickening of the skin. This thickening occurs as a natural defense 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 short or too tight or that exerts friction at specific points can also cause skin thickening that leads to corns and calluses. Abnormalities in gait or movement that result 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 develop in response to using tools, playing musical instruments such as the guitar, or using work equipment that exerts pressure at specific sites.