Thickened nail not always fungus

Conway McLEAN, DPM

In my particular branch of medicine, I have the opportunity to treat a great variety of conditions. It makes for a wonderful and varied work experience, treating as I do, such disparate problems as chronic wounds, sports injuries, bony deformities, neuropathies of all sorts, and many others. Unfortunately, many people’s first thought regarding my profession is that of a nail doctor. And yet, there is a small degree of truth to this misconception.

One of the most common complaints I encounter is that of nail problems. And there are many. Ingrown nails, for example. Likely even more frequent is that of a thickened or yellowed toenail. Often this has been an insidious process, initially subtle and subdued. This condition may escape notice for many months.

Nearly everyone, upon seeing these changes, makes the association: nail fungus! Interestingly, this is often not the case. Many are shocked to find out that a mychotic infection (the technical term for fungus) is responsible only about half the time. There are a host of reasons humans can develop thickening and color changes of a toenail, although it is true, nail fungus is a common problem. (According to the CDC, it has reached “epidemic” status.)

How does one find out what is responsible for your nail changes? Rarely can it be determined from visual inspection alone. The experts agree: the definitive diagnosis of a fungal nail (onychomycosis) can be made, with certainty, only by laboratory testing.

There are a number of different tests that have been used over the years, with more definitive methods being developed of late. As you might guess, genetic testing has come to the world of foot medicine. We can now identify the specific strain of fungal organism which is causing your abnormal nail.

When the causative agent is not fungal, what else can produce such horrific changes? You would likely be surprised at the varied possibilities: the list is quite extensive. For example, the systemic disease known as psoriatic arthritis can cause severe joint changes, but, in addition, many cutaneous changes can occur, including nail changes.

Often these will mimic perfectly a fungus nail, but may not be accompanied by the joint problems or skin changes. Thus, a foot and ankle specialist may be the first health care provider to diagnosis this potentially-disabling disease.

Another critical finding that may be made by a podiatric physician is that of impaired blood flow, peripheral arterial disease (PAD). It turns out skin and skin structures are quite sensitive to a reduction in arterial supply. When clogging occurs in our arteries, limiting the amount of blood passing through, nail changes will typically develop, and these often look just like onychomycosis. Identifying this condition in its early stages can go a long way to preventing the complications of PAD (which include amputation).

Statistically-speaking, the next most common reason for these nail changes may be surprising. As an illustration of this concept, imagine someone hitting their thumb nail with a hammer. After the initial damage heals, frequently the nail will grow back distorted and misshapen. Many are familiar with this circumstance. The root of the nail, which produces the nail plate, was disturbed by the injury. This same phenomenon can occur gradually, over many months, years even, when a nail is pressured or strikes a firm surface repeatedly.

This is what happens for many people inside their shoes. Perhaps their shoes were incorrectly fit (too short!), or not tied tightly, leading to excessive motion. Bent toes (hammer toes) allow the nail to strike the supporting surface with each step, producing subtle nail root injury. The result will be a thickened, misshapen toe nail. And yes, it can look just like a fungus nail, although there is no causative organism. It is not an infection, but the result of physical changes, and thus has a very different treatment.

What are the complications associated with any of these changes? There is a certain social stigma from these, but more of a concern is some of the health ramifications. Fungal organisms residing in the nails can spread to the skin, producing an athlete’s foot infection. Additionally, the abnormal contour of the nail may wear on the skin around the nail, leading to small ulcerations which are hidden by the nail. Bacteria may gain access to the body through these small openings, resulting in cellulitis or sepsis. People who have a compromised immune system, because of medications (steroids!) or disease (diabetes!) can develop severe, dangerous infections as a result. It is recommended these individuals take seriously the treatment of their onychomycosis infection.

How does one treat a thick, yellowed, distorted nail? I hope the message is clear: treatment depends on the cause. Determining why the changes are occurring is the first step. For the sake of our discussion, let’s assume it is fungal in origin. The most common agent is T. rubrum, also the cause of many fungal skin infections. So, you have your nail tested, and lo and behold, it is a T. rubrum infection. At this point, decisions must be made. You could do nothing, but this a progressive, inexorable condition. It will get worse, thicker, more abnormal, with the passage of time. The simplest method of treatment (and also the one with the lowest success rate) is the regular and repeated application of a topical antifungal medication intended for use on nails. There are numerous examples on the market, but many are ineffective. But don’t waste your time with a skin fungus medication: this will have minimal effects since it is not engineered to penetrate the nail, an extremely effective barrier. One technique which greatly aids the power of topicals is reducing this barrier, achieved with thorough debridement, ie professional thinning and trimming, of the affected nail. Thus, removal of this barrier, the nail plate, significantly increases the success rate. Indeed, this is a common adjunctive technique.

What about permanent nail removal? With the rate of complete fungal eradication being so poor, why bother treating? If you don’t have a nail, you can’t have a fungal nail infection! Since a wonderful technique exists to achieve this goal, with an extremely high satisfaction rate, why not remove? Because we wear shoes, nails serve no function. The use of radio-waves to eradicate the nail root leads typically to speedy healing, with an incredibly high success rate.

But methods of treating the fungal infection do exist, and Americans spend millions on them. A prescription oral medicine has been available for years, but the possibility of liver damage deters many from this option. Especially given the fact it’s success rate is only about 60 percent. A light therapy for treating various dermatologic conditions has been around for years but only recently has been used for nail fungus. This is a great option since there are no side effects and boasts a high success rate.

However you treat your fungal nail infection, do so only with the certainty that it actually is a fungal infection. This is one situation where you need to know what you’re dealing with. Onychomycosis is also a shining example of the benefits of seeking treatment early: the longer and more established the fungus becomes, the more difficult to treat. In other words, the success rate plummets as the problem gets worse. As with so many medical problems, get a diagnosis, and then treatment. But do so early in the long course of this resistant, and very common, infectious disease.

Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula, with an upcoming move of his Marquette office to the downtown area. McLean has lectured internationally on wound care and surgery, being double board certified in surgery, and also in wound care. He has a sub-specialty in foot-ankle orthotics. Dr. McLean welcomes questions or comments atdrcmclean@outlook.com.