The Facts

Onychomycosis (OM) refers to a fungal infection of the nails that may affect one or several of the toenails or fingernails.

OM affects about 6.5% of Canadians and is more prevalent among those over 60 years of age and those who have other medical conditions such as athlete's foot, nail psoriasis or trauma, diabetes, or a weakened immune system.

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OM is caused primarily by dermatophytes (a certain group of fungi) and less commonly by other fungi such as yeast.

Fungi are microscopic organisms that don't require sunlight and like to live in warm, moist environments. For this reason, people who swim or whose feet sweat a lot may have a higher chance of getting OM. Because fungi are so small, they can invade your skin through tiny cuts or through a small separation between your nail and nail bed.

OM occurs more commonly in the toenails than fingernails as your toes are often confined in a warm and moist environment inside your shoes. Your toes also have less blood flow than your fingers making it harder for your immune system to stop the infection.

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Symptoms and Complications

OM can cause a nail to:

  • turn white, yellow, or brown
  • get thick, change shape, or lift up
  • break off easily
  • hurt

Fungal nail infections don't usually lead to serious long-term problems when properly treated, but they may be more serious in certain individuals. This can include people with diabetes or who have a weakened immune system and have trouble fighting off an infection. Even if there is no pain associated with the infection, it is important that you promptly visit your doctor for assessment if you see any abnormal nail changes.

Making the Diagnosis

It is important that your doctor confirm you have OM before initiating treatment as there are other conditions that can mimic symptoms similar to OM. Your doctor will conduct an examination of your nail and may take a small scraping from the nail bed to have the lab confirm you have a fungal infection.

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Treatment and Prevention

Your risk of getting OM can be minimized by following these tips:

  • Wear footwear and socks that minimize humidity
  • Keep your hands and feet clean
  • Dry feet and the spaces between your toes thoroughly after washing
  • Wear footwear in shared public spaces such as swimming pools or showers
  • Keep nails clean and cut short
  • Avoid sharing nail clippers or footwear
  • Wear absorbent socks
  • Use antifungal foot powder
  • If you have other health conditions such as diabetes, ensure they're well controlled

Not all cases of OM require treatment with medication but if your doctor has confirmed that you have OM and require treatment due to complications or worsening symptoms, they may prescribe an oral antifungal medication (terbinafine, itraconazole*) based on the type of fungus causing the infection. If you are unable to take oral antifungals or have a mild-to-moderate case of OM, your doctor may opt for a topical therapy (ciclopirox, efinaconazole*) that is applied to the affected nail(s) directly. Topical medications may be less effective than oral medications, but they have fewer side effects such as upset stomach, headache, skin rash, and liver toxicity. If you are prescribed oral medications, your doctor will likely require you to have a liver function test done prior to starting therapy.

Patience is key, as treatment duration varies from 6 to 12 weeks for oral treatments to up to 48 weeks for topical treatment. Because the nails take a long time to grow (6 months for fingernails and 12-18 months for toenails), it will take some time for the infection to resolve and the nail appearance to improve, regardless of the type of treatment used. Sometimes treatment may not be successful and your doctor may prescribe a different medication.

In extreme situations or cases where there is no response to treatment, your doctor may suggest surgical removal of the nail. A new nail will usually grow in its place but may take up to a year. In some cases, surgery may be combined with topical therapy to prevent the infection from recurring.

If you observe any abnormal nail changes it is important to visit your doctor for prompt assessment. In addition to being cosmetically unappealing, OM can also lead to more serious complications, including the possible loss of your nail, bacterial infections, or cellulitis. Speak with your health care provider to determine what the best treatment plan is for you.

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