Athlete’s foot can lead to cellulitis


Are you familiar with the wonders of the microbial world? I realize that many of you likely do not consider this aspect of life on this planet to be so wonderful. The fact that millions of tiny organisms are living on and in your body some find distasteful. Yet, when you consider the essential role that some of them play in our health and well-being, perhaps a change of opinion is warranted. Not so fast; even normally harmless bacteria, under the right (or should I say wrong) circumstances can become pathogenic, ie disease-causing.

Let’s examine the case of Frank, a fine fellow, who was home to a variety of creatures (sounds a little creepy, doesn’t it?). Frank was a recently diagnosed diabetic (although only recently a member of the 40-something’s), who suffered from a recurrent case of athlete’s foot. He considered it a minor annoyance, with occasional itching experienced between a few of his toes. That was the extent of his symptoms, so this was a condition difficult to take seriously. Frank knew diabetes could cause some problems, especially for the feet, but that was the extent of his knowledge, and he thought little more about it.

Frank had tried a few over-the-counter remedies for his athlete’s foot (which means he harbored a fungal infection), but how much trouble could that cause? Fungi are rather interesting (no, really, they are quite fascinating!) and incredibly diverse. Estimates put the number of different types of fungi at 5 million. You read that correctly, five million different species! Their actual numbers are nearly infinite, and perform an essential role in decomposing organic matter. Scientifically, they are considered to be their own kingdom, alongside animals and plants.

Many fungal infections are opportunistic, in that, although you may be unaware of it, they are already part of your environment, but don’t necessarily cause a problem. An actual infection develops only with the right opportunity, a certain situation. This is quite different than some viral infections which cause infection only when you get exposed to them. For specifics, let’s talk about Frank’s toes. Sounds lovely, doesn’t it? (Welcome to my world!) Diabetes can have a tremendous effect on the skin of those afflicted, and can change the natural flora of those organisms, bacterial and fungal, residing on the skin. With the right situation, a proliferation of fungi occurs, and….voila!…tinea pedis, aka athlete’s foot.

Unfortunately, Frank was not properly educated about foot care and skin care since he had not yet been directed to an appropriate medical specialist, one who would provide the essential information about diabetic foot care. He had not been made aware of the dangers of a chronic fungal infection, and their ability to lead to a secondary bacterial infection. The area between the toes has been well-documented to harbor some particularly nasty bacteria, especially when moisture builds up, providing a better environment for fungi and bacteria. An additional factor is the anatomy of the front of the foot. A microbe gaining access to the interior of the foot via the web space, as it’s called, will find itself in one of the deeper chambers of the foot. (Like many parts of the body, the foot is composed of various compartments, with some of the more vital structures generally running through sections closer to the bones, ie deeper.)

In Frank’s case, treatment for the chronic fungal infection was performed only sporadically. Many fungal organisms have a nasty trick in which they will go into a dormant form when conditions are inhospitable. Thus, there will be no visible evidence the fungus is still present. Often, the individual so afflicted will stop the medication because the infection appears to be resolved. This allows the infecting fungus to multiply and thrive once again. Many people will assume that they have picked up a new case of athlete’s foot, when it’s actually the same problem. As often happens, Frank’s fungus caused some blistering, meaning the amazing barrier that skin provides to the interior of the body was breached, and some of those nasty bacteria referred to earlier were able to gain entrance to the foot. The result? Frank came down with a nasty case of cellulitis!

It is at this point that some of you likely are wondering ‘what exactly is cellulitis?’ The term is bandied about, perhaps over-used (meaning some would say it is over-diagnosed), but it is a potentially serious infection. The key to understanding cellulitis is the structure affected: it is a skin infection, and does not spread to deeper layers. Here’s where the body’s system of compartments comes into play. The material that forms the walls of the different chambers, termed fascia, usually prevents the spread of the bacteria into deeper sections. This is by no means a rule, but certainly the trend. This layer, called the dermis, is drained of debris by the lymph system (ever heard of lymph nodes?), so a case of cellulitis certainly can spread via lymph vessels.

Cellulitis most commonly develops on the lower legs. In Frank’s case, the bug gained entrance through the cracks created by the fungal infection, but sometimes there is no apparent route of entry. It can be a real mystery how it got started. When skin is dry or unhealthy, it appears that it provides less of a formidable barrier, and cellulitis occurs more frequently. This is often the case with diabetics, for a variety of reasons. They, as a rule, do not have a particularly effective immune system. Any infection in a diabetic is of great concern, and must be treated promptly. Left untreated, a spreading cellulitic infection can become life-threatening when the individual has some problem with their defense system.

Frank, who did have diabetes, noticed a rapidly spreading area of redness and warmth, along with some chills and a mild fever. Swelling and tenderness, also hallmarks of the condition, were noticed. This bright young fellow (remember, he did just turn 40!) realized at this point something had to be done. Fortunate for Frank, his cellulitis was caused by a bacterium that was not particularly virulent (ie dangerous and aggressive). This can make a tremendous difference in the course of the disease. Cellulitis caused by the infamous (and now famous) MRSA, a type of staph infection, can be resistant to many of our antibiotics, including most of the oral ones.

Prevention is the best method of treatment, keeping the feet (and area between the toes) as clean as possible, and providing good skin care. Once cellulitis has developed, getting on the appropriate antibiotic quickly is crucial. Usually, an oral antibiotic is sufficient, but when one of the more resistant bugs is responsible, administering a stronger antibiotic, via an IV, is often required. Early recognition and treatment is key. Once again, don’t ignore foot problems: they may not bite you, but they will kick you!

Editor’s note: Dr. Conway McLean is a podiatric physician now practicing foot and ankle medicine in the Upper Peninsula, having assumed the practice of Dr. Ken Tabor. McLean has lectured internationally on surgery and wound care, and is board certified in both, with a sub-specialty in foot orthotic therapy. Dr. McLean welcomes questions, comments and suggestions at