How to Treat Toenail Fungus

The visible appearance of recalcitrant toenail fungus is dismaying.


Few conditions carry the visible stigma of toenail fungus. Toenails are a visible representation of vitality.  We also decorate our toenails thus making them an emblem of fashion. Unfortunately, treating toenail fungus or tinea unguium is difficult, and results take a while to appreciate—new and healthy toenails can take up to a year to grow in.

What Is Toenail Fungus?

Onychomycosis refers to toenail infection caused by fungus, most typically dermatophytes (and less typically by yeasts and even molds).

Toenail fungus usually clouds the nail bed with a gnarled and turbid-yellow appearance. Toenail fungus can also change the topology of nail bed and result in a raised, thickened, and scaly or flaky surface. Infected nails can appear brittle or crumbled around the edges. Onychomycosis can effect one, two, many or all toenails.

In the United States, toenail fungus aggravates about 2 to 13 percent of all people; the FDA estimates that 35 million people, mostly adult men aged 50 to 70, are affected by this condition. On a related note, fingernail fungus is rare, affecting only 0.15 percent of the population. Toenail fungus usually infects adults and hits the distal portion of the nail bed (part of the nail farther away from your body).

Here are some factors that put you at risk for onychomycosis:

  • swimming
  • immunosuppression (think HIV or chemotherapy)
  • living with a person who has this condition
  • trauma (can not only predispose a person to infection but also be confused with infection)

Toenail fungus has a pretty typical appearance and can also cause inflammation and pain. Nevertheless, toenail fungus can be diagnosed using KOH or dermaotophyte test medium.

Such diagnostic testing entails sending a culture or sample (toenail clipping) to the lab; results from this testing can take 3 to 7 days to report.

How Is Toenail Fungus Treated?

Toenail fungus is notoriously difficult to treat. For the most part, topical treatments don't work because they don't penetrate the nail bed. Oral treatment works best but takes time to cure as the nail needs to first grow healthy. (If you've ever had your big toenail fall off, then you know that it can take 6 to 12 months for it to grow back. )

Terbinafine is likely more effective than griseofulvin when treating toenail fungus. Fortunately, this drug is now generic and affordable. After diagnosis of onychomycosis, your physician will likely prescribe you once-daily oral terbinafine for 3 long months. Rarely can terbinafine poison your liver (result in hepatotoxicity). Nevertheless, your physician will likely check your liver enzymes both before and during your course of terbinafine treatment. Terbinafine cures about 76 percent of toenail infections.

In addition to daily dosing, terbinafine treatment can be "pulsed" at 250 mg taken two times a day for one week per month. Please remember to discuss specific medications and dosages with your physician.

Griseofulvin, on the other hand, is dosed once-a-day at either 500 mg microsized or 350 mg ultramicrosized and must be taken with a fatty meal. Depending on the severity of infection, higher doses may be necessary. Griseofulvin can cause adverse effects such as gastointestinal distress, headache, and urticaria or hives. For nail infections, it is taken for a very long 6 to 18 months to treat, and relapse rates are common with cure rates clocking in at about 60 percent.

Itraconazole can be taken in addition to terbinafine. Itraconazole has more drug interactions than does terbinafine and can be taken daily or given in pulses (pulse dosing), with pulse dosing being more effective.

Both itraconazole and terbinafine are equally effective at treating toenail fungus. In other words, a physician can administer 200 mg every day or 200 mg twice-a-day for one week per month. Itraconazole is also used to treat causes of fungus other than dermatophytes. Toenail infections are typically treated for 3 months.

As previously mentioned, itraconazole can have some serious reactions with other drugs that are metabolized by P450 enzyme system. If you are on multiple medications, itraconazole may be the wrong drug for you.

A nail lacquer cicolopirox (Penlac), has shown limited promise in treating toenail fungus; it only cures about 8 percent of those taking it. Of note, Penlac may be useful as treatment in those who can't tolerate oral therapy or as adjuvant, or additional, treatment along with surgical removal of toenails.

In June 2014, the FDA approved Canadian drug Jublia for the treatment of onychomycosis. Jublia is the first drug for treatment of onychomycosis that can be applied directly to the nail as liquid. In clinical trials, Jublia was at least 15 percent effective, ostensibly making it more effective than Penlac.

Sometimes raised toenails infected by fungus become inflamed, painful and even pus filled. The raised nail harbors not only fungus (dermatophytes) but also keratin, or skin debris. In these cases, the nail should probably be removed surgically. 

Although fluconazole is not FDA-approved for the treatment of onychomycosis, or toenail fungus, emerging research on the off-label use of this antifungal medication as treatment is promising. Moreover, therapies other than medication are currently being explored for the treatment of toenail fungus including phototherapy and laser.

What to Do With Toenail fungus?

Oral therapy for toenail fungus works but because oral medications have adverse effects, you need to team with your physician so that she may monitor treatment. Furthermore, you must remain vigilant and commit many months to treatment with the expectation that cure won't be overnight. If you're pregnant or breastfeeding, don't take oral antifungal medications. 

With respect to toenail fungus, preventive measures are vitally important. Do your best to wear slippers or flip-flops in community settings like locker rooms and public showers. 


Lawley LP, McCall CO, Lawley TJ. Chapter 52. Eczema, Psoriasis, Cutaneous Infections, Acne, and Other Common Skin Disorders. In: Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 18e. New York, NY: McGraw-Hill; 2012.

"Treating Onychomycosis" by T. Rodgers and M. Bassler from American Family Physician and published in 2001.

Usatine RP, Smith MA, Chumley HS, Mayeaux EJ, Jr.. Chapter 193. Onychomycosis. In: Usatine RP, Smith MA, Chumley HS, Mayeaux EJ, Jr.. eds. The Color Atlas of Family Medicine, 2e. New York, NY: McGraw-Hill; 2013. 

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