title: The prevalence of onychomycosis in the global population: a literature study.
abstract: BACKGROUND
  Onychomycosis is a common disorder, and high prevalence figures are commonly cited in the literature.
  
  
  OBJECTIVE
  Evaluate the prevalence of onychomycosis based on published studies.
  
  
  METHODS
  Relevant studies were identified in Medline by using specific search criteria.
  
  
  RESULTS
  Eleven population-based and 21 hospital-based studies were identified. The mean prevalence in Europe and North America was 4.3% [95% Confidence Interval (CI): 1.9-6.8] in the population-based studies, but it was 8.9% (95% CI: 4.3-13.6) for the hospital-based studies. Both population-based and hospital-based studies showed that onychomycosis is more common in toenails and is seen more frequently in males. The main causative agent was a dermatophyte in 65.0% (95% CI: 51.9-78.1) of the cases. Trichophyton rubrum was the single most common fungus and was cultured on average in 44.9% of the cases (95% CI: 33.8-56.0). Moulds were found on average in 13.3% (95% CI: 4.6-22.1) and yeasts in 21.1% (95% CI: 11.0-31.3).
  
  
  CONCLUSIONS
  We may not have been able to locate all studies.
  
  
  CONCLUSIONS
  Onychomycosis is a common disorder, but it may not be as common as cited in the literature, because hospital-based studies might overestimate the prevalence of onychomycosis. It is more frequent in males, and toenails are more commonly affected. Dermatophytes, particularly T. rubrum, are the main causative agents.
authors.affiliation: Faculty of Medicine, Department of Dermatology, University of Iceland, Reykjavík, Iceland.
authors.forename: B
authors.initials: B
authors.lastname: Sigurgeirsson
authors.forename: R
authors.initials: R
authors.lastname: Baran
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000453:epidemiology; D000368:Aged; D000369:Aged, 80 and over; D001208:Asia / Q000453:epidemiology; D002648:Child; D005060:Europe / Q000453:epidemiology; D005260:Female; D005533:Foot Dermatoses / Q000453:epidemiology* / Q000382:microbiology; D014943:Global Health; D006229:Hand Dermatoses / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D014009:Onychomycosis / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D013020:South America / Q000453:epidemiology; D014005:Tinea / Q000150:complications; D014249:Trichophyton; D055815:Young Adult