Is it a Wart or a Corn?

Two issues I often see in clinic are corns and warts. While they may seem similar due to their appearance on the skin, they are caused by very different factors and require different treatment approaches. In this post, we'll dive into the key differences between the two as well as how each condition is treated. 

What Are Corns? 
Corns are a type of callus. They are thickened, hardened areas of skin that develop in response to pressure or friction. They typically appear on the feet in areas where there is repeated rubbing or pressure. The rubbing is often associated with a nearby bony prominence. As the skin is repetitively subjected to forces between the bone and the ground, shoe gear, or other bone, the skin hardens to protect itself from breaking down into a wound by forming a callus. The affected area can become painful, especially when pressure is applied. This is often due to the thickened skin pressing against nerves or other tissues. Corns are not contagious. 

What Are Warts? 
Warts, on the other hand, are caused by a viral infection — specifically, the human papillomavirus (HPV). Warts can develop anywhere on the body, including the feet. When they occur on the bottom of the feet, they are often referred to as plantar warts. Warts can also cause pain, especially when pressure is applied while walking. 
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The HPV virus that causes warts can enter the skin through tiny cuts or abrasions. The virus spreads easily in warm, moist environments, making areas like public showers, swimming pools, and locker rooms common places where you can pick them up. Warts are contagious and can spread to different parts of the body, to others in your household, or to anyone who interacts with the same surfaces that you do. 
 
How to Tell Difference Between Corns and Warts 
Before getting into tips on telling the two apart, I would like to take a moment to advocate for getting a professional evaluation of any new or changing skin issues that you may encounter. Obviously, there are far more than just two types of skin lesions, and just because a spot on your skin that has findings consistent with those of warts or corns does not necessarily mean that is what you are looking at. Some types of skin cancers can present in ways that mimic the appearance of these lesions. These can even occasionally fool experienced physicians, but the trick doctors use is to constantly be asking ourselves what else it could be. Should it not respond to treatment in the way we would expect, or if there are subtle differences from what we’ve seen before, we will often consider something like a biopsy to ensure we’re on the right track and not missing anything.  
 
Another important point is that treatments, even at-home and over-the-counter remedies, might not be appropriate for all patients. Age, medical conditions, and environmental factors can influence how safe or how well different treatments can work. Professional evaluation can help put your mind at ease and potentially save your life. So, with that out of the way... 
Warts often have a distinctive, bumpy appearance, often with small black dots in the center. These small black dots are blood vessels that your body tries to push through the warty tissue to fight the infection. There can be a single bump, numerous bumps, or even clusters. When we debride the wart (using a sharp tool to remove superficial tissue, don’t try this at home), we will often see pinpoint bleeding. There will generally be interruptions in the skin lines across the warts. 
Corns are typically small, round, and hard to the touch. They often have a dense center. Skin lines usually go all the way through the lesion, though there can be interruptions at the core. While the black dots seen in warts are not generally present in corns, repetitive trauma to the skin under the corn can lead to bleeding and a dark spot. 
 
How Are Corns Treated? 
Rather than focusing solely on treating symptoms, I like to understand underlying causes. Symptomatic treatment for corns typically focuses on removing the thickened skin. One way this can be accomplished is with applications of OTC products like Urea. I find that because much of a corn can exist under the skin, topicals like salicylic acid generally only provide a few days of relief and can damage the surrounding skin. Another symptomatic treatment is to cut out the core with a scalpel, which can give lasting relief. DO NOT TRY THIS AT HOME. I have seen patients develop abscesses and even require amputations due to trying to cut these out themselves. If you wish to pursue this treatment, let me or another professional handle the sharp stuff. These treatments will not keep the corns from coming back! 

The best way to treat corns, in my opinion, is to prevent them in the first place. Because pressure is usually causing these issues, removing the pressure is the best way to keep these from coming back. The pressure may be due to your foot shape, your gait, your shoes, fat pad atrophy,   
 
How Are Warts Treated? 
There are many ways to treat warts, each having their own pros and cons. There are over-the-counter treatments like salicylic acid, cryotherapy which involves freezing the wart off, laser therapy or electrosurgery which burns the wart off, surgical excision which cuts the wart out, various chemical agents to destroy the wart, or the use of oral antiviral agents.  
One of the difficulties in treating these is the potential for scar formation. When I was younger I had a wart burned off my finger by my family doctor at the time. The treatment was successful at destroying the wart, but it also left a large wound that took weeks to heal and I still have a scar on that finger. It’s not in a place that it causes issues, but scar tissue on the bottom of the foot has the potential to cause discomfort with every step. My goals in treatment do not include my patients thinking about me every step they take for the rest of their lives. The most common way I treat warts is the application of a chemical once every two weeks, with an average of about 3 treatments. This resolves over 95% of the cases I see and does not lead to scarring. In the rare case that does not work, I have found surgical excision to be an effective treatment. 

In conclusion, though corns and warts may seem similar, they have distinct causes and require different treatment approaches. Corns are caused by friction or pressure, while warts are a viral infection. Whether you're dealing with a painful corn or a bothersome wart, understanding the difference and seeking the right treatment can help you achieve relief and protect your foot health. If you're unsure which condition you're dealing with or if over-the-counter treatments aren't working, schedule an appointment with us for a personalized treatment plan!