title: The prevalence of unsuspected onychomycosis and its causative organisms in a multicentre Canadian sample of 30 000 patients visiting physicians' offices.
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.
  
  
  CONCLUSIONS
  The present data highlights that onychomycosis may be a growing medical concern among ageing patients.
authors.affiliation: University of Toronto Department of Medicine, Toronto, ON, Canada.|Mediprobe Research Inc., London, ON, Canada.
authors.forename: A K
authors.initials: AK
authors.lastname: Gupta
authors.affiliation: Wayne State University, Detroit, MI, USA.
authors.forename: G
authors.initials: G
authors.lastname: Gupta
authors.affiliation: Private Dermatology Practice, Cambridge, ON, Canada.
authors.forename: H C
authors.initials: HC
authors.lastname: Jain
authors.affiliation: University of Toronto Department of Medicine, Toronto, ON, Canada.|Lynde Institute for Dermatology, Markham, ON, Canada.
authors.forename: C W
authors.initials: CW
authors.lastname: Lynde
authors.affiliation: Mediprobe Research Inc., London, ON, Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Foley
authors.affiliation: Mediprobe Research Inc., London, ON, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Daigle
authors.affiliation: Mediprobe Research Inc., London, ON, Canada.
authors.forename: E A
authors.initials: EA
authors.lastname: Cooper
authors.affiliation: Sporometrics Inc., Toronto, ON, Canada.
authors.forename: R C
authors.initials: RC
authors.lastname: Summerbell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009819:Office Visits; D014009:Onychomycosis / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D055815:Young Adult