The term onychomycosis brings together the prefix “onycho”, which refers to nails, as well as the suffix “mycosis”, which refers to an infection caused by fungus.


Therefore, onychomycosis is commonly called “nail fungus” and can attack toenails. It’s a contagious infection that spreads very easily from one toenail to the next.

This infection is often not worrisome, as it usually affects the skin first. It’s often found in the form of athlete’s foot. It can spread to other areas of the body, including toenails. Several parts of the nail can be affected, including the root, the nail bed (bottom of the nail) and the nail plate (visible part of the nail). It has a yellowish colour and a flaky appearance. The infection will initially be aesthetically disturbing, but as the infection progresses there may be pain or discomfort.


Onychomycosis is caused by harmful microorganisms growing in places where there is a mix of humidity, heat, and darkness. That’s the reason why it’s most often found in feet.

Onychomycosis isn’t always easy to identify because it can resemble other conditions or problems. It can be due to poor personal health practices or to a very long tobacco consumption. Diabetes, poor blood circulation or a weakened immune system may also be causes of this condition.

To avoid developing onychomycosis, you must wash your feet properly daily, keep them as dry as possible by changing your socks when they are wet and by drying your feet after a shower (don’t forget those spaces between your toes!), keeping your nails short and clean, wearing suitable shoes and using properly disinfected nail care tools. You should also avoid walking barefoot in public places. Pool season is coming, so be careful and wear sandals when travelling for your next swim. Don’t forget to change your shoes, as they may have become obsolete!


Onychomycosis must absolutely be treated to avoid contamination. Treatment for the condition will be given depending on how the body responds to it. However, it is very important not to try to cover it up, such as by putting on nail polish, for example.

Clinical examination or obvious observations can lead to a quick conclusion of the diagnosis. Following the condition’s assessment, our podiatrist will recommend a treatment plan for you. Keep in mind that our podiatrists can prescribe the same medications as your family doctor or a dermatologist to treat the infection. The advantage of consulting with one of our podiatrists is that you will have specific care for your condition. Deep debridement of the nail and progress monitoring will always be part of treatment plan.

The treatment for onychomycosis will follow these steps:

  1. Cutting and deep debridement of affected nails.
  2. Combined with drug therapy (depending on the condition).
  3. Visits according to the frequency established with the podiatrist.

The more the treatments plan will be regular and followed as established, the more likely the onychomycosis will be controlled. In fact, it will take an average of 6 weeks for the thinning of the nail combined with the medication to take effect. Of course, that always depends on the infection’s progress and extent.

The condition’s improvement varies depending on each patient. One of our podiatrists at the Clinique podiatrique St-Charles will keep the infection under control to allow the affected toenails to return to their closes normal appearance.

Ideally, you should prevent onychomycosis as much as possible, and if you do catch it, seek treatment as soon as possible. If you see a slight change in the appearance of your nail, don’t wait to consult us. The sooner you see one of our podiatrist, the sooner the treatments will work, and the infection will be under control.