Onicomicoses: Perfil de fungos não dermatófitos em pacientes ambulatoriais da Fundação Alfredo da Matta - Manaus/Amazonas

Abstract

The role of non-dermatophyte fungi, as it is controversial in the pathogenesis of onychomycosis, requires careful laboratory examination. Both filamentous fungi and yeasts can mimic the dermatophytoses. In this context, this research aimed to observe the mycological profile of nondermatophytic fungi on the etiology of onychomycosis in patients from the Amazon Region and to relate the etiological agents to the types of lesions and the probable predisposing factors. We examined 25 volunteers of both genders presenting 61 nails with lesions suggestive of onychomycosis. The collected clinical material was submitted to clarification with 40% Potassium Hydroxide solution. For the isolation of fungi, part of the clinical material was seeded on Sabouraud agar with chloramphenicol (100 mg / L) and Sabouraud agar plus chloramphenicol (100 mg / L) and 1% olive oil, both cultures were incubated at 25 ° C e 37ºC, respectively. The growth of the microorganisms was observed, every 24 hours, for 30 days. From the 25 patients examined, in 20 the parasitism by filamentous fungi and / or yeasts was confirmed. From the 61 ungual samples, in 72% (44) onychomycoses were diagnosed. According to the results obtained, the onychomycosis patients, 65% female and 35% male, had an age range of 31-50 years old (50%). Among these, there were patients with only hands fingernails (50%), only 25% of the toenails. In the others, 25% had both toenails and hands nails. The professional activity with the largest number of patients was housekeeper (25%), in which the nails of the hands (19%) were more affected. Concerning nails, the halluxes (40.91%) were the most affected. Distal-lateral subungual onychomycosis (OSDL) was observed in 66% of cases, mainly affecting the toenails (43%). The contact with moisture was the most important risk factor reported by patients who had hand nail injuries (45%). The prevalence of non-dermatophytic fungi (90.9%) was observed, among which yeasts were the most frequent (52.7%). Mixed infections (18%) by non-dermatophytic fungi affected 18% of the nails. Among the 53 isolates, 98% of the Deuteromycota phylum and 2% of the Ascomycota phylum were observed. Candida albicans was the predominant species (30%). Among non-dermatophyte filamentous fungi, Aspergillus candidus (4%) and A. niger (4%) were the most frequent. In 8% of cases, Trichophyton tonsurans were diagnosed. Candida albicans was predominant in single agent onychomycosis (28%) affecting mainly female toenails (9%) and male hand nails (9%) occurred more frequently in patients from 31 to 40 years old (12 %), With subungual distal-lateral onychomycosis (16%) being the most common clinical form. It is suggested, with the results of this research, on the etiology of onychomycosis, that non-dermatophyte fungi - both yeasts and filaments - cannot be excluded only by clinical examination, alerting to the importance of laboratory examination and, thus, increasing the chance of success.