The prevalence of unsuspected onychomycosis and its causative organisms in a multicentre Canadian sample of 30 000 patients visiting physicians' offices

J Eur Acad Dermatol Venereol. 2016 Sep;30(9):1567-72. doi: 10.1111/jdv.13677. Epub 2016 May 11.

Abstract

Background: Onychomycosis is difficult to treat and a concern for many patients. Prevalence estimates of onychomycosis in North American clinic samples have been higher than what has been reported for general populations.

Objective: A large, multicentre study was conducted to estimate the prevalence of toenail onychomycosis in the Canadian population.

Methods: Patients were recruited from the offices of three dermatologists and one family physician in Ontario, Canada. Nail samples for mycological testing were obtained from normal and abnormal-looking nails. This sample of 32 193 patients includes our previous published study of 15 000 patients.

Results: Abnormal nails were observed in 4350 patients. Of these, the prevalence of culture-confirmed toenail onychomycosis was estimated to be 6.7% (95% CI, 6.41-6.96%). Following sex and age adjustments for the general population, the estimated prevalence of toenail onychomycosis in Canada was 6.4% (95% CI, 6.12%-6.65%). The distribution of fungal organisms in culture-confirmed onychomycosis was 71.9% dermatophytes, 20.4% non-dermatophyte moulds and 7.6% yeasts. Toenail onychomycosis was four times more prevalent in those over the age of 60 years than below the age of 60 years.

Conclusion: The present data highlights that onychomycosis may be a growing medical concern among ageing patients.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Canada / epidemiology
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Office Visits*
  • Onychomycosis / epidemiology*
  • Onychomycosis / microbiology
  • Prevalence
  • Young Adult