Onychomycosis in Tehran: mycological study of 504 patients

Abstract

Onychomycosis is a common nail disorder resulting from the invasion of the nail plate by a dermatophyte, yeast or mould species and gives rise to some diverse clinical presentations. The purpose of the present study was to isolate and identify the causative fungi of onychomycosis in the population of Tehran, Iran. Nail samples from 504 patients with prediagnosis of onychomycosis during 2005 were examined both by direct microscopical observation of fungal elements in KOH preparations and in culture for the identification of the causative agent. All samples were inoculated on (i) Sabouraud dextrose agar (SDA, Merck), (ii) SDA with 5% chloramphenicol and cycloheximide in duplicate for dermatophyte and (iii) SDA with 5% chloramphenicol in triplicate for mould isolation. The criteria for the diagnosis of onychomycosis caused by non-dermatophytic moulds were based on microscopical observation of fungal elements, growth of the same mould in all triplicate culture and no growth of a dermatophyte or yeast in all the cultures. Of 504 cases examined, 216 (42.8%) were mycologically proven cases of onychomycosis (144 fingernails, 72 toenails). Among the positive results, dermatophytes were diagnosed in 46 (21.3%), yeasts in 129 (59.7%) and non-dermatophytic moulds in 41 (19%). Trichophyton mentagrophytes was the most common causative agent (n = 22), followed by Trichophyton rubrum (n = 13), Candida albicans (n = 42), Candida spp. (n = 56) and Aspergillus spp. (n = 21). Nearly half of the clinically suspected fungal nail infections are onychomycosis and yeast is responsible for most of the infections in Iran.

Molecular Analysis of Candida species with Emphasis on Predisposing Factors in Cutaneous Candidiasis Patients

“…Similar to other studies conducted in other regions of the world, our study confirmed that onychomycosis was the principal clinical presentation (56.9%) (30)(31)(32). Moreover, this form of infection has been found more often in female than male (33,34). This trend could be attributed to their activities because most of the affected females were working at home (defined as housewife in Table 3).…”

Aspergillus species as emerging causative agents of onychomycosis

“…The occurrence of 135 cases of Aspergillus nail infection in one year at the two medical mycology laboratories in Tehran is remarkable, and together with previous studies on onychomycosis in Tehran and in some other parts of the country, our data suggest that Aspergillus spp., mainly A. flavus, are somewhat commonly involved in NDM onychomycosis in Iran [8,10,18,27]. Unlike almost all studies performed in Iran, in our survey, the frequency of onychomycosis due to yeasts and NDMs exceeds the frequency of nail infections caused by dermatophytes [18]. This high occurrence was similar to that of Scherer et al who found a shift from dermatophytes to saprophytes as agents of nail infections [33].…”

“…Saprophytic onychomycosis can be caused by various fungi, including Scopulariopsis brevicaulis, Aspergillus spp., Fusarium spp., Acremonium spp., and Scytalidium spp. [6,7,10,16,18,28,37]. Some epidemiological studies indicate that Aspergillus is an emerging cause of toenail onychomycosis, and after Scopulariopsis it is the most common cause of nondermatophyte mold onychomycosis [13].…”

Leveduras do gênero Candida isoladas de sítios anatomicamente distintos de profissionais militares em Cuiabá (MT), Brasil

“…22 Cases of yeast infection of the nail were reported in the scientific literature by investigators evaluating onychomycoses in 504 patients in Tehran. 23 Onychomycoses were confirmed in 216 (42.8%) of the 504 cases analyzed. Those authors found yeast infections in 129/216 cases (59.7%), the most common causal agents being Candida albicans (n=42) and Candida spp (n=56).…”

“…Similar findings were also reported in Iran, Algiers, Canada and Italy, these investigators reporting the isolation of yeasts in fungal infections of the nail. 14,23,27,28 Investigators in Brazil conducted dermatophytic screening at the Araraquara Health Unit and found 15 cases of yeast infection (16.2%). 29 The results obtained in the present study, in which 23 cases of Candida yeast infection were detected in the toenails, a rate of 15.2%, are in agreement with the findings of the abovementioned investigators.…”