corns: a horny growth of thickened skin, often with a central seed of hardened, dead skin cells

Did you ever wonder why a hard, unsightly growth on the side of the toe is called a “corn”? It’s easy to see how the name evolved. First, a corn grows out of the skin like a small horn (think stunted unicorn). Next, a corn often has a small, hardened cluster of skin cells that can be described as a kernel, a plug, or a seed. The term has been around since the 1300s, and, though it’s not pleasant to visualize, it’s easy to see why the name stuck.

The terms “corn” and “callus” are sometimes used interchangeably, which is understandable since they both refer to a thickening and hardening of the skin. Both also develop exclusively from too much pressure being applied to a particular area of the skin. However, though the cause is similar, there are a number of differences between corns and calluses. “Calluses generally appear on weight-bearing surfaces, such as palms and soles,” says Robert S. Fawcett, M.D., medical director at York Hospital Family Medicine Residency in York, Pa. Corns, on the other hand, occur on non-weight-bearing surfaces in regions of extra pressure, such as overlying the joints of the toes.”

Another difference between corns and calluses is the way in which the hardened skin forms. Calluses are flatter and generally wider than corns. Think of the callus as protecting the skin from repeated aggravation: the body forms a thick, protective layer of skin to protect the repeated assault. Calluses often appear on knees of surfers, floor installers, or the very devout. They also appear on elbows and hands. Corns are formed less from the body building protection, and more as a warning sign that something is pressing too tightly against the skin. Corns can sometimes be difficult to differentiate from warts, “although warts obscure skin lines, and corns do not,” notes Dr. Fawcett. Another distinguishing characteristic between a corn and a wart is the “root.” “Paring down a corn one often sees a central plug or seed formed from keratin (dead skin cells). Paring down a wart reveals a series of black dots, which are really capillaries in the center of the wart,” says Dr. Fawcett.
No tests are needed to confirm a person has a corn. They are identified and diagnosed just by how they look. Often, a corn will have a soft yellow ring surrounding it and a white or grayish center. It may or may not be painful to the touch, but many times it is painful when pressure is applied to it.

While the cause of a corn is always pressure, the cause of the pressure can be different among clients. Some pressure is formed simply from ill-fitting, tight, or pointed shoes. In this case, corns often form on the outside of the small toe. However, sometimes corns form at the site of another problem, such as a bunion or hammertoe, or where rheumatoid arthritis has inflamed the joints.

Women are more likely to develop corns than men, because, though our shoes are cuter, they’re not always ergonomically friendly. The elderly would seem to be more likely to develop corns as age often brings arthritis; however, often by the time arthritis is threatening, the aged have opted for better, more comfortable footwear, removing the pressure from their feet. “Children generally do not get corns,” says Dr. Fawcett. “Though, particularly with the recent obesity epidemic, they may be more prone to calluses, since they are carrying more weight.”

Treatment for corns is to remove the pressure, and the pressure is most often removed by changing footwear. Often, with a change of shoes, a corn will heal on its own. Many people find relief during healing by placing a donut-shaped pad over the corn. The pad sticks to the skin like a Band-aid and relieves pressure from the corn. Other protective pads, such as toe wraps and toe separators, are available at any drugstore. Most of the time a corn will not need medical treatment, but if there is pain at the site, a client may want to go to the doctor to have the corn pared down, which can provide immediate relief. Another treatment recommendation is to use salicylic acid, but many caution against this. In cases where the corn is due to the structure of the bones and joints, a doctor’s visit to diagnose and treat the underlying problem is necessary.


What’s a Tech to Do?

Techs will notice when a client has developed or is developing a corn because the skin will begin to thicken. Remember, it’s always due to pressure. Talk with the client about the corn, discussing her shoe choices, the level of pain, and the duration of the development. Ultimately, it’s up to the client if she wants to leave the corn alone or do what’s necessary to remove the pressure and allow it to heal. If there is no pain involved, no treatment is necessary, and a client may prefer to wear cute shoes and just live with the corn.

Unlike a callus, a corn doesn’t respond well to abrasive treatment. A client with a callus may ask you to buff away the hardened skin. However, buffing a corn is likely to cause pain. A warm footbath will soften the skin and make it less tender to the touch, but “lateral movement of a corn is very irritating,” says Dr. Fawcett. Do not remove a corn even at a client’s request, especially in the case of a client with diabetes. It’s possible that the skin could be compromised while trying to remove or buff a corn, leaving the client at risk of infection. Let her know that the corn is likely to heal itself when the pressure is removed, but if she wants it to be removed immediately, she needs to schedule an appointment with her doctor. Always recommend a doctor’s visit if you suspect the corn is due to a problem with a client’s joints or bones instead of, or in addition to, her footwear.

For reprint and licensing requests for this article, Click here.