[Onychomycoses caused by non-dermatophytic filamentous fungi in Cádiz]

Abstract

Background: The incidence and clinical significance of other than dermatophytes fungi or moulds causing onychomycosis is unknown, because they may be colonising organisms rather than pathogen. This report presents the results of a study conducted between 1997 and 1999 to determine the incidence and aetiology of onychomycosis by non-dermatophytic filamentous fungi in the population of Cádiz (Spain).

Patients and methods: Diagnosis of onychomycosis was performed by direct microscopic examination, culture and, some times, by histologic examination, on samples from 610 patients with clinical suspected fungal nail infections.

Results: Among 196 (32%) cases of ungual mycosis detected, 29 (15%) of them were caused by non-dermatophytic filamentous fungi, presenting positive direct microscopy and repeated cultures. Superficial and distal onychomycosis were the most frequent clinical types. Twenty two patients had onychomycosis of toenails. The highest incidence was found in women and subjects over the age 40. Scopulariopsis spp. (n = 11), Aspergillus spp. (n = 6), Alternaria spp. (n = 5) and Fusarium spp. (n = 4) were the most common fungi. Occasionally, Acremonium spp. and Scedosporium spp. were isolated.

Conclusion: The incidence of onychomycosis caused by opportunistic fungi is not well known. For their diagnosis, it is important to select correctly the appropriate site for specimen collection, as well as direct microscopy and fungal cultures. The incidence of onychomycosis is high in Cádiz (Spain), being higher in women and older people. Predispondent factors are not always identified in the patients. Toenails were infected more than fingernails in both sexes. The results of our study suggest that Scopulariopsis spp. is an important agent of onychomycosis. Epidemiological investigations should be performed in every country in order to determine the fungal species responsible of onychomycosis.