A large-scale North American study of fungal isolates from nails: the frequency of onychomycosis, fungal distribution, and antifungal susceptibility patterns.
BACKGROUND
Onychomycosis, a fungal infection of the nail bed, is responsible for up to 50% of nail disorders. Although several surveys have been conducted in different parts of the world, there have been no multicenter epidemiologic surveys of onychomycosis in North America.


OBJECTIVE
A 12-center study was undertaken to (1) determine the frequency of onychomycosis, (2) identify organisms recovered from the nails, and (3) determine the antifungal susceptibility of isolates.


METHODS
A total of 1832 subjects participated in this study and completed a comprehensive questionnaire, and nail clippings were collected for potassium hydroxide examination and culturing.


RESULTS
The frequency of onychomycosis, as defined by the presence of septate hyphae on direct microscopy and/or the recovery of a dermatophyte, was found to be 13.8%. In general, the dermatophyte isolates were susceptible to the antifungals tested.


CONCLUSIONS
Because of the limited number of large-scale studies, the baseline incidence is not firmly established. However, the higher frequency of onychomycosis in this study may confirm the suspected increase in incidence of disease in North America.
Ghannoum
M A
MA
Department of Dermatology, University Center for Medical Mycology, Cleveland, OH 44106-5028, USA.
Hajjeh
R A
RA
Scher
R
R
Konnikov
N
N
Gupta
A K
AK
Summerbell
R
R
Sullivan
S
S
Daniel
R
R
Krusinski
P
P
Fleckman
P
P
Rich
P
P
Odom
R
R
Aly
R
R
Pariser
D
D
Zaiac
M
M
Rebell
G
G
Lesher
J
J
Gerlach
B
B
Ponce-De-Leon
G F
GF
Ghannoum
A
A
Warner
J
J
Isham
N
N
Elewski
B
B
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000935:Antifungal Agents / Q000494:pharmacology; D002170:Canada; D002648:Child; D002675:Child, Preschool; D005260:Female; D005533:Foot Dermatoses / Q000453:epidemiology / Q000382:microbiology; D006229:Hand Dermatoses / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D014009:Onychomycosis / Q000453:epidemiology* / Q000382:microbiology*; D014481:United States
D000935:Antifungal Agents