title: Prevalence and epidemiology of onychomycosis in patients visiting physicians' offices: a multicenter canadian survey of 15,000 patients.
abstract: A prospective, multicenter study to determine the epidemiology of onychomycosis was performed in the offices of 3 dermatologists and 1 family physician in Ontario, Canada. In the sample of 15,000 patients, abnormal-appearing nails were observed in 2505 persons (16. 7%). There were 1199 patients (8%) with toenail or fingernail onychomycosis confirmed on mycologic examination, with 1137 patients (7.6%) who had only pedal onychomycosis, 40 patients with toenail and fingernail onychomycosis (0.27%), and 22 patients (0.15%) with only fingernail onychomycosis. The condition was more common in male patients (P <.0001) and older persons (P <.0001). The ratio of onychomycosis in toenails/fingernails was 19:1. When onychomycosis was present in toenails, the ratio of distal/lateral subungual onychomycosis (DLSO) to white superficial onychomycosis to proximal subungual onychomycosis was 360:59:1. The extent of DLSO in toenails was mild (< or =25% nail involvement), moderate (26%-74% disease), and severe (> or =75% nail involvement) in 27.6%, 39.9%, and 32.5% of patients, respectively. After adjusting for the age and sex distribution of the general population, the projected rate of onychomycosis in Canada is 6.5% (95% confidence interval [CI], 6. 1%-6.9%). The organisms causing toenail onychomycosis were 90.5% dermatophyte, 7.8% nondermatophyte molds, and 1.7% Candida spp. The corresponding organisms causing fingernail onychomycosis were 70.8%, 0%, and 29.2%, respectively. In a large sample of 15,000 patients, abnormal-appearing nails were present in 17% of the sample with mycologic evidence of toenail or fingernail onychomycosis in 8%. The projected prevalence of onychomycosis in Canada is 6.5% (95% CI, 6. 1%-6.9%).
authors.affiliation: Division of Dermatology, Department of Medicine, Sunnybrook and Women's College Health Sciences Center (Sunnybrook site), and the University of Toronto, Canada.
authors.forename: A K
authors.initials: AK
authors.lastname: Gupta
authors.forename: H C
authors.initials: HC
authors.lastname: Jain
authors.forename: C W
authors.initials: CW
authors.lastname: Lynde
authors.forename: P
authors.initials: P
authors.lastname: Macdonald
authors.forename: E A
authors.initials: EA
authors.lastname: Cooper
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; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009819:Office Visits; D014009:Onychomycosis / Q000453:epidemiology*; D015995:Prevalence