Nail fungus, also medically known as onychomycosis, is a chronic fungal infection of the fingernails and/or toenails by dermatophytes, yeasts and molds leading to gradual destruction of the nail plate. According to the National Institutes of Health, it is more likely to affect toenails, particularly the first toenail, than fingernails. A large questionnaire survey of 10,000 people in the United Kingdom suggests that it is present in 2.71 percent of the population, while more recent surveys in Finland and in the United States suggested that 7 to 10 percent of the population is affected.
An infected nail often will have unsightly white/yellow or orange/brown patches or streaks. It can also turn thicker, crumbly, ragged or dull, according to the Mayo Clinic. In some cases the nail will emit a slightly foul odor and it may separate from the nail bed, a process known as onycholysis.
Diagnosis & Tests
Although 50 percent of all nail disorders can be categorized as onychomycosis, it is not always possible to identify the disease accurately by just looking at the symptoms, according to a treatment guideline commissioned for the British Association of Dermatologists. Other conditions, such as psoriasis, can result in similar nail abnormalities as well. Once the above symptoms are observed, lab tests consist of microscopy to visualize fungal elements and a mycological culture to help identify the species of microbes involved will provide a more definitive diagnosis. Since onychomycosis is primarily a disease of the nail bed rather than of the nail plate, skin debris and samples taken from the spot closest to the infection is likely to yield the best results, according to the British guidelines.
Treatment & Medications
Onychomycosis is not self-healing and may be a source of more widespread fungal lesions on the skin, or vice versa. Both topical and oral treatments are available.. Oral antifungal medications such as terbinafine (commonly marketed under the trade name Lamisil), itraconazole (Sporanox) and fluconazole (Diflucan or Trican) encourage the growth of new, non-infected nail, while slowly cycling out infected portion of the nail, according to the Mayo Clinic. The medication is usually taken for six to 12 weeks, but a toenail may take up to 78 weeks to grow fully and preventative measures should be taken during that gap to avoid recurrent infection.
Over-the-counter antifungal creams and ointments generally do not help cure onychomyocis because of poor penetration into the nail, according to the NIH. However, some nail lacquers have shown to be somewhat effective in a large study where only nails infected at the free edge were treated.
Successful eradication of the fungus may still leave the nail looking permanently abnormal because of trauma to the nail bed and nail plate by the disease, according to a 2007 article published in the Journal of the American Academy of Dermatology. Therefore a cure should be based on lab tests and not on visual appearance.
The fungi that cause onychomycosis thrive in warm, moist areas such as public swimming pools, gyms or shower rooms, according to the NIH. General hygiene practices such as keeping all nails short, dry and clean by regular trimming will help decrease the risk of infection. One should avoid going barefoot in public places, particularly public showers, and choose a reputable salon that properly cleans and disinfects its manicure and pedicure instruments.