Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android



  • Onychomycosis is a very common fungal nail infection and the vast majority of cases are caused by dermatophytes.

  • Fungi can invade the nail utilizing multiple mechanisms, thereby yielding distinct clinical patterns.


  • Think of onychomycosis if proximal border of onycholysis shows spikes at dermoscopy.

  • Look for tinea pedis/tinea manum.

  • Sampling sites depend on clinical subtypes of onychomycosis.

  • The gold-standard diagnostic tools are KOH with light microscopy, fungal culture, or histopathology with fungal stains.

  • PCR is very sensitive and fast, but can cause false positive results.


  • Oral terbinafine and itraconazole are approved treatments for onychomycosis.

  • Oral terbinafine is the most effective treatment for dermatophyte infections.

  • Oral antifungals can be administered as pulse therapy with similar efficacy.

  • Topical antifungals are only approved for mild/moderate diseases limited to distal nails.

  • Topical antifungals can be utilized to prevent relapses/recurrences.

  • Efficacy should be assessed after several months due to slow nail grow.

  • In most cases the affected nails will not be clinically normal even when onychomycosis is cured.


  • Involvement of all fingernails is against a diagnosis of onychomycosis.

  • Assess patient’s liver function and drug interaction before prescribing oral antifungals.


  • Common misconceptions:

  • Nail infections are just cosmetic problems and do not have major health impact.

  • Oral antifungal medication will certainly damage liver functions.


  • If a patient comes in with fingernail disease, look at his or her toenails, and vice versa.

  • Tell affected patients to put on their socks before their underwear to prevent fungal auto-inoculation to groin area.


  • Onychomycosis is an infection and needs to be treated.

  • Nails grow slowly and take several months to see any clinical improvement.

  • Complete clinical cure is not always attainable due previous traumatic damages.

  • Personal hygiene and treating individuals within the household are important to reduce the chance of relapse.


Onychomycosis accounts for more than half of all nail-associated disorders1 and nearly 90% of all nail infection.2 This disease causes significant cosmetic damages and discomfort to patients and poses continuous challenges to treat curatively due to poor response to treatment and frequency of recurrences. Patients also have impaired sense of psychosocial wellbeing as nails are important parts of the personal presentation to the outside world. Therefore, it is substantial to make a timely diagnosis and deliver effective treatment.

KOH, fungal culture, and histology are the gold standard techniques for diagnosis. PCR is emerging as it provides fast results even if possibly too sensitive. Oral antifungals are the first-line treatment with better cure rates and shorter treatment periods than topical treatments, but can have adverse side effects such as hepatotoxicity and drug interactions. Prophylactic topic medications and certain behaviour modifications are important to prevent relapse.3



Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.