Why It's Essential To Treat Onychomycosis As An Infection

Dr. Joseph: The fact that onychomycosis is an infection is often overlooked. It is a fungal infection of the nail and the nail bed stratum corneum. There is no other infection anywhere on the body that we think twice about treating, but for some reason, this is an infection that we’ve always been reluctant to treat.
Just to give you an example, one of my kids came home once with a case of ringworm on his arm. The school nurse sent a note saying that he was not going to be allowed back in school unless he had a note from the doctor saying the ringworm of his arm was under active treatment. Ringworm of the arm is basically a fungal infection of the skin caused by the exact same organism that causes the fungal infection of the skin of the toes. It is a T. rubrum fungal infection. It’s tinea corporis.

When the infection is on a visible part of the body, it causes great consternation and concern. As soon as you hide it in a shoe and a sock, people just don’t seem to care about it. This is going to become especially important for our diabetic population. What infection in a diabetic don’t we treat immediately? Yet for some reason, people don’t think this is important enough to treat.
As an infection, onychomycosis can progress. We know it can start in one part of one toenail and spread throughout that toenail. It can jump from one toenail to another. It can move from skin to a toenail to other parts of the body, and it can actually move from one patient to another. As an infection, onychomycosis can also recur following treatment. It can lead to serious local and systemic sequelae.
Onychomycosis causes major quality of life issues, embarrassment, sexual dysfunction and pain. Approximately 50 percent of patients have pain with this disease.1 We should also be aware of the potential complications for patients with diabetes and the whole concept that onychomycosis acts as a reservoir for infection. In other words, there is a nasty cycle going on here. The bottom line is this is a disease that needs to be treated.

What Statistics Reveal
About The Gaps In Diagnosis And Treatment
Dr. Joseph: We know onychomycosis is a common disease. It has been estimated that 35 million patients in the United States have onychomycosis but only 6.3 million people have actually been diagnosed with onychomycosis because they are the ones who have come to physicians’ offices and actually had the condition diagnosed.2 That tells you there are approximately 29 million people walking around out there with onychomycosis who have never been seen by a physician for onychomycosis and never been formally diagnosed with onychomycosis.
In regard to the 6.3 million patients who have been diagnosed with the condition, they account for about 11 million office visits.2 This tells us the average patient is seen about twice a year by doctors when they have this disease. In short, onychomycosis is an extremely common and under-diagnosed infection that really needs to have more attention paid to it.
We know onychomycosis increases with age. About 60 percent of patients with onychomycosis are 55 or older. Even if you look at these numbers, you will see that 20 percent of patients diagnosed with onychomycosis are between 30 and 45 years of age. That’s incredibly young. Another 22 percent of these patients are between 65 and 74 years of age.2 These are still the active elderly years for many patients so we do need to aggressively treat these patients and try to cure their onychomycosis.
If you look at prescribing habits that are out there, the numbers are truly amazing to me. For the aforementioned patients who are between 30 and 45, about 85 percent of them receive some sort of prescription for onychomycosis. That number starts dropping precipitously as the age of the patient goes up. In the 46 to 54 age group, only about 75 percent of patients receive any prescription.2 That means 25 percent of these patients are leaving their podiatrists or their physician’s office without having any active treatment for this disease. I really think we can do better.

When it comes to the aforementioned active elderly age group, those between the ages of 65 and 74, less than a third of patients in that age group (31 percent) who have been diagnosed with onychomycosis actually receive a prescription to treat the disease.2
I think we’ve got a lot of room for improvement in treating this disease considering the number of patients who have been diagnosed with it. Then again, that is not even addressing the 29 million who have not yet been diagnosed with the condition.

A Closer Look At The Epidemiology Of The Disease
Dr. Joseph: When you look at the natural history of the disease, onychomycosis starts as tinea pedis and then gets up under the toenails and sets up shop. Now we have tinea pedis and onychomycosis. The patient may come in to you for tinea pedis, which you can treat either orally or topically, but if you don’t get rid of the onychomycosis, you are going to get the tinea pedis back. Likewise, once you get rid of onychomycosis, if you don’t keep the tinea pedis away, the patient is going to get the onychomycosis back. These two diseases are inexorably linked so we need to manage both of these diseases.
Let’s take a closer look at the epidemiology of onychomycosis. Whenever you look at any sort of disease state, you have to look at the host, the environment and the pathogen. We know the pathogen in onychomycosis tends to be T. rubrum, the dermatophyte. I don’t care what you may believe or what you heard years ago. At least 90-plus percent of all onychomycosis is caused by T. rubrum. This is good news because we know that we can address the pathogen. We know we can use antifungals, whether they are topical or oral, to effectively destroy the pathogen.
Unfortunately, if you look at the epidemiology, we also have two other variables that come into play: the environment and the host. When it comes to the environment, we are talking about the patients’ shoe gear, including their insoles, which are harboring the spores. We are also talking about their overall hygiene, whether or not they’re walking around with bare feet on pool decks or in public showers, or even walking on carpets in hotel rooms or in the house. Do their feet sweat a lot? If so, they may have very moist inner spaces, which predispose to tinea pedis and subsequently leads to onychomycosis.
Fortunately, we can address the environment. We can have the patient change shoes. We can have patients dry their feet with various drying solutions or antifungal powders. They can use topical antifungals in their shoes to kill the organisms. They can wear slippers or flip-flops if they’re going to be at the swim club and walking around the pool.
What we can’t address is the host and we know there is a unique host-parasite relationship when you’re looking at onychomycosis and tinea pedis. When Zaias did genetic mapping of families many years ago, he showed that there is an autosomal dominant trait that confers that cell mediated immune deficit that makes the patient predisposed to chronic T. rubrum infection.3
We can’t do anything about the host but what we can do is address the environment and kill the pathogen. By doing these things, we can manage this disease.

Addressing Relapse And Reinfection
Dr. Joseph: As far as relapse and reinfection go, I’d first like to provide some definitions. Relapse, which is pretty synonymous with recurrence if you look in Stedman’s Medical Dictionary, is a return of manifestations of the disease after an interval of improvement. In other words, the foot is getting better, the toenail is getting better and before it totally cures, it suddenly gets worse. This tends to imply that something went wrong with the therapy. That does happen in the treatment of onychomycosis, but I don’t think it’s our major issue. I think our major issue is reinfection. Reinfection, according to Stedman’s Medical Dictionary, is defined as a second infection by the same microorganism after the recovery from the primary infection.4 In other words, we’ve managed to cure that onychomycosis. The toenail is better and the skin is clearer but because of the patient’s genetic predisposition eventually the toe becomes infected again.
You will see reinfection with this disease. People frequently ask me about the reinfection rate with onychomycosis. I tell them it’s 100 percent. Because of this genetic predisposition, unless the patients are properly managed, everybody who has onychomycosis and was treated is going to get it back.
What are the hard numbers? What data do we have? Tosti’s study, which was a very small study of three arms — the original study only looked at 20 patients per arm — compared two dosing regimens of terbinafine versus one dosing regimen of itraconazole. This study showed that in three years, 22 percent of the patients experienced a relapse of onychomycosis.5 That’s pretty good. However, something must happen between the third and fourth years, because if you look at a different set of data by Heikkila and Stubb in the British Journal of Dermatology, they found after four years, only one-third of patients remained cured. That means two-thirds of patients had a relapse.6
Who knows what would happen by year five, year six or by year seven if we did not properly manage these patients? My guess is you will see reinfection in 100 percent of the patients.

Pearls For Encouraging Patient
Awareness And Compliance
Dr. Joseph: So what are we going to do about it? We manage by using maintenance regimens of antifungals. Although never really studied, booster dosing of orals has been suggested with perhaps two weeks or a month of terbinafine once a year or once every six months. What about using topical antifungals such as ciclopirox nail lacquer once or twice a week? You could suggest having Fungal Friday, Toenail Tuesday or something like that to get the patient to remember to use the medication. It makes sense because if you apply the antifungal to the nail, you should prevent fungus from being able to get hold and cause infection after it has been cleared up. I have to point out, though, that none of this has been studied. It’s all empiric. There is no good hard data for any of these regimens.
We know onychomycosis starts as tinea pedis. We also know their tinea pedis is going to be gone once their onychomycosis is cured because the antifungal that worked against the onychomycosis tends to work against the tinea pedis. You have to use topical therapy on the skin from now until the cows come home. Basically, it’s ad infinitum topical therapy. It doesn’t have to be daily. It can be a few times a week, but again, this has never been studied.
There are also common sense suggestions for managing the patient. Have them discard old shoes. If patients can’t discard old shoes, just have them change their inner soles. Tell them to alternate between different pairs of shoes so they can allow them to dry out. This helps prevent the feet from getting moist as this predisposes them to infection. Disinfecting the shoes has never been studied.
The last point I want to make is telling the patients to alert you at the first sign of reinfection. You have to educate your patients so they understand that once it starts coming back, they need to come in right away because it’s much easier to treat when we catch it early.

Is Onychomycosis Prevalence On The Rise?
Dr. Cervantes: You have shown very interesting data on how many millions of people have onychomycosis and yet such a low percentage of patients are being treated. It’s amazing. There’s a big gap there that needs to be addressed.

Dr. Joseph: That’s a great point, Dr. Cervantes. I’ll even go one step further. If you look at prescribing data, we see that even of the patients who are in the podiatrist’s office specifically for onychomycosis, on any given month of the year, only 50 percent of podiatrists are actively writing for either prescription topical antifungals or oral antifungals for onychomycosis. Not only is there a big gap between those patients who are thought to have onychomycosis versus those who have actually been diagnosed with onychomycosis, there is a pretty big gap between those who have been diagnosed with onychomycosis and those who are actually receiving treatment for onychomycosis.
Dr. Mozena: Dr. Cervantes actually brought up an interesting point on how many people are infected by onychomycosis. Looking at the condition from a historical perspective, onychomycosis wasn’t introduced in the United States until 1928 when the first case of tinea was reported. If onychomycosis affects 2 to 3 percent of the general population now, what does this mean for the future? Will this number continue to rise? I think we need to recognize that this is a dynamic number that seems to be growing. Given this, has fungus now become part of our natural flora? If that is the case, does that mean, with time, all populations will have this particular problem?
Dr. Cervantes: I think the incidence of onychomycosis will increase because the incidence of obesity is increasing. We know this is an issue here since obesity obviously leads to diabetes. We also know onychomycosis is present 2.8 times more among patients with diabetes.7 We will most likely see an increase as far as the numbers go.
Dr. Joseph: I think it’s inevitable that we’re going to end up seeing more onychomycosis. As the population gets older, we’ll see more of the condition because it is more common as you get older.
Dr. Malkin: Boni Elewski, MD, has talked about the fact that onychomycosis is literally epidemic and she can trace it across the world.
Dr. Malay: Also, as Dr. Joseph pointed out, it’s important to recognize that onychomycosis affects a very broad age range from young patients to older patients. In recent years, since I’ve been back in the city of Philadelphia, I’ve seen a lot of young patients, even pediatric, adolescent and young adult patients, with onychomycosis that’s quite extensive and advanced. When you see this condition in younger patients, you should be suspicious of some type of immune deficit. You should at least look into that with a CBC and a biochemical profile so you do not miss something that may be bigger than just the fact that they have onychomycosis.

Discussion Point: Emphasizing Effective Approaches
To Patient Education And Compliance
Dr. Malkin: We need to take the treatment of onychomycosis seriously. For example, in my practice, I take photographs of almost every patient that I am treating actively for onychomycosis. Nothing is better than to pull out a Polaroid that’s in their chart to show them what their disease looked like in the beginning and what it looks like now. We need to be very quantitative from visit to visit. Is it improving? Isn’t it improving?
Dr. Malay: Your patients certainly want you to take it seriously. If all you do is debride and tell them to come back in three months or something, you know they are going to come back with the same abnormal nail three months later if they are not doing something in the interim between visits. My patients tell me they feel better doing something during that interval as long as they feel that it is effective and they can see some type of improvement. They’re perfectly willing to do it as long as they can get the medication and get to their toes to put it on.
Dr. Joseph: Onychomycosis takes work to treat. Even if you are prescribing an oral medication, you are not just giving a pill. You have to explain to the patient what the oral is and explain potential complications. You have to do bloodwork and you still have to debride. It’s the same with the topical. You have to get the patient actively involved, which means having him or her get down there every day, applying it every five to seven days and removing the excess. We really have to get the patients to buy into the disease. As Dr. Malay said, I think patients want to be treated. I think it’s our hang-up as a profession that we don’t want to effectively treat this condition, that we just want to debride.

Dr. Mozena: Dr. Joseph, you talked about psychological concerns and you brought up this great point about patients not being able to go in the swimming pool and, in some cases the patient may have a sexual dysfunction. I had a case in which one of my patients would not take off her socks during her honeymoon because of her onychomycosis. This is a psychological concern. You also referred to the study that indicated that 48 percent of the patients with onychomycosis have pain.1 It’s not just that we have a problem with onychomycosis as an infection, but it can also cause psychological issues as well as pain.
Dr. Malkin: We have all been talking about primary treatment of onychomycosis. What about the slew of patients that present for bunion surgery at Dr. Malay’s office or in other types of situations in which onychomycosis is not the chief complaint? Do you recognize this is a disease? Now if you went to the dentist because you had pain in your right upper quadrant and he didn’t examine the rest of your mouth to see what else was going on, would you feel he was a good dentist or not? If a patient comes in with skin disease, nail disease or something else that’s very obvious, it’s incumbent upon us to diagnose it, present it to the patient and treat it. It may not be treated immediately with priority being given to the chief complaint, but it certainly should be addressed before the patient is discharged. I think this is a big area of practice management and quality of patient care issue that we seem to miss out on.
Dr. Joseph: I think we have to restate the whole point that this is an infection and if it’s explained to the patient as an infection, what patient is not going to want to treat it?
Dr. Malkin: It’s an infection that won’t go away on its own. The public relations data from Lieberman showed that was the key to having patients accept definitive treatment. That was the key take-home message for patients to make them want to treat it.8
Dr. Malay: It’s indolent and slowly progressive. We have been talking about the question of whether fungus is becoming normal flora. That’s interesting. I think with some of the advertisements that pharmaceutical companies have made in recent months, it seems anecdotally to me there’s more people coming in and specifically saying they want to treat this. Even when I look at very early cases, there may be some dystrophy or discoloration of the nail but it doesn’t look to me to be fungal. They’re still thinking fungus and that’s good because public education is an important thing.

Add new comment