Onychomycosis by Scytalidium dimidiatum: report of two cases in Santa Catarina, Brazil

Abstract

Onychomycoses constitute pathologies frequently seen in dermatological practice worldwide. Usually, they are caused by two groups of pathogenic fungi: dermatophytes and yeasts of the Candida genus. However, in a small fraction of the cases, the etiologic agents comprise nondermatophyte molds, belonging to several genera and species. The objective of this study was to present two cases of onychomycosis associated to the mold Scytalidium dimidiatum in patients residing in two cities of Santa Catarina State, Brazil. Aspects of fungal pathogenesis, as well as the epidemiological characteristics and laboratory diagnosis, are discussed.

Nattrassia mangiferae: An uncommon agent of onychomycosis

“…4 Case reports describing N. mangiferae as a cause for cutaneous mycosis have been published in Brazil. 1 Two such cases of onychomycosis have been described in green tea leaf pluckers from North-eastern India by Barua et al 7 From the clinical point of view, the lesions caused by N. mangiferae are often similar to those caused by dermatophytes. The affected nails display dystrophy and onycholysis, as it was also observed by us in this case report.…”

“…The role of N. mangiferae as etiological agent of onychomycosis has been known since 1970, when Gentles & Evans isolated it from cases of dermatomycoses and onychomycosis. 1 They named the isolated fungus as H. toruloidea. Later, Campbell & Mulder reported a patient with identical disease to which they named the etiological agent Scytalidium hyalinum.…”

“…Later, Campbell & Mulder reported a patient with identical disease to which they named the etiological agent Scytalidium hyalinum. 1,5 Afterward, genetic studies showed that the two species were phylogenetically very close to each other and the name Scytalidium, comprising the species S. hyalinum and Scytalidium dimidiatum were then considered the most appropriate taxonomic designation. 1 Lacaz et al reported two cases of onychomycosis, one of them in an HIV positive patient, caused by S. dimidiatum.…”

“…The clinical picture though variable is characterized by alterations in the nail architecture such as changes in color, thickness, onycholysis and onychodystrophy. 1 In most cases they are caused by filamentous fungi like dermatophytes or yeasts of the genus Candida. 2 However, in a small fraction of cases, the etiological agent comprises of non-dermatophyte molds, belonging to several genera and species.…”

“…2 However, in a small fraction of cases, the etiological agent comprises of non-dermatophyte molds, belonging to several genera and species. 1,3 The prevalence of non-dermatophytic onychomycosis varies widely, depending on the geographical location or the climate, but is more frequent in hot and humid tropical areas. 3 They are often considered contaminants or secondary pathogens that invade nails previously damaged by trauma or disease.…”