Dr. Conway McLean, Journal columnist

These pages often tell the tale of the latest epidemic or important disease, but not today. You won’t be seeing any headlines on the front page of your daily news about a fungus infection. But they are an integral part of our world and a necessity for the planet to be able to support life. There are innumerable species of fungi in the world, over 5 million, and several hundred cause human disease. But they are nature’s recycling system, breaking things down into simpler forms so that they might re-enter the cycle of life.

Fungal infections can develop in many tissues, given the right (wrong, from the patient’s perspective) circumstances. These are generally considered opportunistic infections, meaning that if conditions are not good for them, these organisms may be present but do not necessarily cause infection. They need the right opportunity, like a warm, moist shoe after the wearer’s busy workday.

Athlete’s foot infections, what is more correctly termed tinea pedis, have afflicted mankind for centuries. Fungal infections are a nuisance to the healthy, but a serious threat to the immune-compromised. Naturally, there are many different types of fungal infections, but they share the attribute of being resistant to eradication; they are a challenging life form to kill.

Many fungal infections, once they have developed, never resolve, and stay with the host for the rest of his or her life. If one occurs in the lung, the treatment itself is potentially debilitating, and the success rate low. This likewise is true for toenail infections. If not caught relatively early in this slow but inexorable process, it typically remains there, gradually, slowly worsening, for the remainder of their life.

The form of tinea pedis most often depicted in ads or tv is that of the interdigital sort, as in between the toes. This generally develops quickly, and for the healthy individual, it usually can be resolved with a little attention. But ignoring these can be dangerous, even for the young. Not infrequently, when a fungus “sets up shop” in this area, a secondary bacterial infection develops.

Statistically more common than the interdigital variety is a chronic fungal infection of the bottom of the foot, especially the arch and sides of the foot. This type is far less obvious, producing fewer signs and less symptoms. It usually manifests as simply some scaling and peeling skin with a subtle redness. Mild itching may be noted but little else. This situation may remain for many months, causing little complication. And then, an especially active day or a foot that stays too wet will allow a flare of the tinea. Symptoms become evident, as does a significantly increased risk of a bacterial invasion.

A healthy immune system prevents the more dire consequences of a tinea infection. But someone taking immune-suppressive drugs (such as an organ transplant recipient) or a person with diabetes is more likely to experience this secondary bacterial infection. And to a diabetic, these can be limb threatening.

70% of the population will be infected with tinea pedis at some time, although it was not always so. Some studies claim it was the increased use of occlusive shoe gear that led to its spread globally in the latter half of the 1900’s. Also, a factor in the increased incidence has been the trend toward urbanization, greater use of fitness facilities, the growing prevalence of obesity, the aging population, and especially the rising epidemic that is diabetes. Individuals with this disease need to treat tinea quite differently. An athlete’s foot infection can and has led to hospitalization and amputation. The tinea leads to small cracks in the skin, allowing bacteria in.

The previously mentioned fungal nail infection is also epidemic and consists of fungal organisms invading and colonizing the nail region. These are the epitome of a chronic infection, leading to some dangerous changes to the nail plate such as thickening and curving (into the toe itself!). This means the individual that is harboring a fungal nail has a reservoir of these bugs hanging out inside their shoe. Even if conditions are not good for spreading to skin, eventually it will, leading to tinea pedis.

The treatment of tinea is quite simple for many of us. The regular use of an antifungal cream may be all that is required. Topical medications have good access to the fungus since it resides strictly in the skin layer, never penetrating into deeper tissues (without a wound present). There are oral medications for fighting fungal infections but are rarely required when the immune system functions adequately.

Most of the specific species which can cause tinea are spore formers. These spores are a sort of hibernation, allowing fungi to withstand harsh or unfavorable conditions for long periods. This altered form can “live” inside a shoe for ages. Patients with tinea pedis need to be educated about reinfection. Too often, they are re-exposed to the fungi residing in their shoes. It is not enough to use a topical on the skin; shoes should be treated as well. They should either be disposed of or treated with a shoe spray intended for this purpose.

Populations living in humid, tropical environments are more at risk, as are those suffering from hyperhidrosis (excessive sweating). Those using shoe gear which tends to trap moisture are also. Use of communal bathing facilities, like the local gym are more likely to be exposed to these organisms. As mentioned, impaired immune function is also a factor. Naturally, genetics is a critical component, as always.

Recognizing the presence of these sometimes requires an astute observer with a thorough knowledge of these microbes. A biopsy of some superficial scaling skin can provide a definitive diagnosis after analysis by a pathologist. That is often the first challenge to vanquishing these long-lived infections: identification. Then an on-going plan to prevent recurrence.

These organisms don’t do anything quickly, especially resolve. Persistence with an effective topical agent, along with a consistent reduction of the moisture content of the shoe’s interior, will resolve most cases of tinea. The conversation changes for those who have diabetes; they need to treat superficial skin conditions, like tinea pedis, more precisely, more thoroughly. If you are diabetic, or you know someone who is, have them get a thorough assessment. These are infections it’s not okay to live with.