With spring officially here and — believe or not — beach weather around the corner, millions of American will expose their toes. Some will be more self-conscious about it than others, because of a disease called onychomycosis, better known as nail fungus.
Nail fungus usually affects toenails, but can also affect fingernails. It turns the nails yellow, makes them potentially brittle, creates growth underneath the nail (thickening of the nails) and may cause pain.
Many patients are bothered by this disorder. Most patients consider getting treatment for cosmetic reasons, but there are also medical reasons to treat, including the chronic or acute pain caused by nail cutting or pressure from bedsheets and footwear. There is an increased potential risk for infections, such as cellulitis, in those with compromised immune systems (1). Onychomycosis is not easy to treat and can be quite uncomfortable.
Onychomycosis affects approximately 8 percent of the population (2). The risk factors are unclear, but may be relate to family history, tinea pedis (athlete’s foot), older age, swimming, diabetes, psoriasis, suppression of the immune system and/or living with someone affected by it (3).
There are a number of organisms that can affect the nail. The most common class is dermatophytes, but others are yeast (Candida) and nondermatophytes. A test commonly used to differentiate the organisms is a KOH (potassium hydroxide) preparation, which is a simple microscopic exam of skin and nail shavings. This is important since some medications work better on one type than another. Also, yellow nails alone may not be caused by onychomycosis; they can be a sign of the autoimmune disease psoriasis.
There are a plethora of therapies available for treatment. These range from over-the-counter alternative therapies to prescription topical medications to systemic, or oral, prescription therapies to laser therapies and, finally, surgery. I am regularly asked which treatment works best.
With all of these options, how is one to choose? Well, there are several important criteria, including effectiveness, length of treatment and potential adverse effects. The bad news is that none of the treatments are foolproof, and the highest “cure” rate is around two-thirds. Oral medications tend to be the most efficacious, but they also have the most side effects. The treatments can take from around three months to one year. So there is no overnight success. Unfortunately, the recurrence rate of fungal infection is thought to be approximately 20 to 50 percent with patients who have experienced “cure” (4).
Fortunately, most cases of nail fungus are benign, with only a fraction leading to infections. Infection is most common in those with diabetic neuropathy, where the patient loses feeling in their feet.
Let’s look at the evidence.
There are several options for oral antifungals, including terbinafine (Lamisil), fluconazole (Diflucan) and itraconazole. These medications tend to have the greatest success rate, but the disadvantages are their side effects.
In a small but randomized controlled trial, terbinafine was shown to work better in a head-to-head trial than fluconazole (5). Of those treated, 67 percent of patients experienced a clearing of the fungus in their toenails with terbinafine, whereas 21 percent and 32 percent experienced these benefits with fluconazole, depending on the duration. The patients in the terbinafine group were treated with 250 mg of drug for 12 weeks. Those in the fluconazole group were treated with 150 mg of drug for either 12 weeks or 24 weeks, with those in the 24-week group experiencing the better results. Thus, this would imply that terbinafine is the more effective drug. This is a small trial, but the results are intriguing. The disadvantage of terbinafine is the risk of potential hepatic (liver) damage and failure, though it’s an uncommon occurrence. Liver enzymes need to be checked while using terbinafine. Its advantages are the efficacy and the duration.
Another approach to reduce side effects is to give oral antifungals in a pulsed fashion. In a RCT, fluconazole 150 mg or 300 mg was shown to have significant benefit compared to the control arm when given on a weekly basis (6). However, the efficacy was not as great as with terbinafine or itraconazole (7).
A commonly used topical medication is ciclopirox (Penlac). The advantage of this lacquer is that there are minor potential side effects. However, the disadvantages are that it takes approximately a year of daily use, and its efficacy is not as great as the oral antifungals. In two randomized controlled trials, the use of ciclopirox showed a 7 percent “cure” rate in patients, compared to 0.4 percent in the placebo groups (8). There is also a significant rate of fungus recurrence. In this trial, ciclopirox had to be applied daily for 48 weeks. These results were in patients with mild to moderate levels of fungus in the surface area of the infected nails.
Of the treatments, laser therapy would seem to be the least innocuous. However, there are very few trials showing significant benefit with this approach. A study with one type of laser treatment (Nd:YAG 1064-nm laser) did not show a significant difference after five sessions (9). This was only one type of laser treatment, but it does not bode well. To make matters worse, many of the laser treatments are not covered by insurance, and they can be expensive. Another research paper that reviewed the current literature concluded that laser therapies are lacking in randomized clinical trials (10).
The advantage of laser treatment is the mild side effects. The disadvantages are the questionable efficacy and the cost. We need more research to determine if it is effective.
Vicks VapoRub may have a place in the treatment of onychomycosis. In a very small pilot trial with 18 patients, 27.8 percent or 5 of the patients experienced complete “cure” of their nail fungus (11). Additionally, partial improvement occurred in the toenails of 10 patients. But what is more interesting is that all 18 patients rated the results as either “satisfying” or “very satisfying.” The gel was applied daily for 48 weeks. The advantage is low risk of side effects and low cost. The disadvantages are a lack of larger studies for efficacy, the duration of use and the lower efficacy compared to oral antifungals.
So when it comes to onychomycosis, what should one do? None of the treatments are perfect. Oral medications tend to be the most efficacious, but also have the most side effects. If treatment is for medical reasons, then oral may be the way to go. If you have diabetes, then treatment may be of the utmost importance. If you decide on this approach, discuss it with your doctor; there are appropriate precautionary tests, such as liver enzyme monitoring with terbinafine (Lamisil), that need to be done on a regular basis. However, if treatment is for cosmetic reasons, then topical medications or alternative approaches may be the better initial choice. No matter what you and your physician agree upon as the appropriate treatment, have patience. The process may take a while; nails, especially in toes, grow very slowly.
(1) J Am Acad Dermatol. 1999 Aug.;41:189–196;Dermatology. 2004;209:301–307. (2) J Am Acad Dermatol. 2000;43:244–248. (3) J Eur Acad Dermatol Venereol. 2004;18:48–51. (4) Dermatology. 1998;197:162–166; uptodate.com. (5) Pharmacoeconomics. 2002;20:319–324. (6) J Am Acad Dermatol. 1998;38:S77. (7) Br J Dermatol. 2000;142:97–102; Pharmacoeconomics. 1998;13:243–256. (8) J Am Acad Dermatol. 2000;43(4 Suppl.):S70-S80. (9) J Am Acad Dermatol. 2013 Oct.;69:578–582. (10) Dermatol Online J. 2013 Sep. 14;19:19611. (11) J Am Board Fam Med. 2011;24:69–74.
Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, go to the website medicalcompassmd.com or consult your personal physician.