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Advances in dermatology and venereology Acta Dermato-Venereologica
Onychomycosis Due to Arthrinium arundinis: A Case Report
Mariusz DYLĄG 1, Anita HRYNCEWICZ-GWÓŹDŹ 2 and Tomasz JAGIELSKI 3 *
1
Department of Genetics, Institute of Genetics and Microbiology, University of Wrocław, 2 Department of Dermatology, Venereology and Allergology, Wrocław Medical University, Wrocław, and 3 Department of Applied Microbiology, Institute of Microbiology, University of Warsaw, I. Miecznikowa 1, PL-02-096 Warsaw, Poland. * E-mail: t. jagielski @ biol. uw. edu. pl Accepted Apr 6, 2017; Epub ahead of print Apr 17, 2017
The genus Arthrinium comprises an environmentally and biochemically diverse group of ascomycetous fungi, most of which display an endophytic lifestyle in a wide range of plant species. To date, only Arthrinium phaeospermum has been implicated in human disease, as a causative agent of superficial infections.
We describe here a case of subungual onychomycosis, due to A. arundinis. Treatment with itraconazole and amorolfine was successful in this case.
CASE REPORT
1 https:// www. medicaljournals. se / acta / content / abstract / 10.2340 / 00015555-2673
Fig. 1. Clinical and mycological characteristics.( A) The big toe nail plate before treatment, and( B) after 3-month therapy with oral itraconazole and topical 5 % amorolfine.( C) Hyphae of Arthrinium arundinis visualized by direct examination of nail scrapings after 10 % KOH and dimethyl sulfoxide treatment( original magnification 1,000 ×).( D) Macroscopic appearance of A. arundinis culture on potato dextrose agar medium post 14-day incubation at 25 ° C.( E) Lactophenol cotton blue-stained slide culture showing the microscopic morphology of A. arundinis( original magnification 1,000 ×; scale bar 5.26 μm).( F) Scanning electron microscopy( SEM) of the fungus,( original magnification 10,000 ×; scale bar 1 μm).
In January 2016 a 42-year-old man was examined in the Mycological Laboratory in the Department and Clinic of Dermatology, Venerology and Allergology, Wrocław Medical University, Wrocław, Poland. He presented with a typical distal and lateral subungual onychomycosis( DLSO) of the big toenail of the left foot. The nail plate was approximately 70 – 80 % affected, with yellow-grey discoloration and advanced hyperkeratosis. The surface of the nail plate was neither eroded nor deformed. Only a single transverse nail ridge was observed on the border of the lunula, relating to anamnestic trauma. Here, the nail plate was thickened, separating the affected region from the healthy tissue. There was empty space between the nail plate and nail bed. The detachment of the nail plate from the periungual tissue was also visible, especially on the lateral side( Fig. 1A). Apart from insulin-dependent diabetes, the patient was in good general condition. Neither systemic disease nor any use of immunosuppressive drugs was evidenced in the patient’ s history. Approximately 4 months earlier he had struck his foot on a piece of wood while walking barefoot along the shore of the Baltic Sea. A splinter entered deeply under the nail plate, and was removed immediately and nail was disinfected with octenidine hydrochloride solution( Octenisept ®). After approximately one month the patient noticed a small wedge-shaped alteration on the nail. During the next 3 months, he intermittently used topical Scholl Fungal Nail Treatment ®, with no effect. The lesion subsequently spread over approximately 75 % of the nail plate.
Mycological examination was performed, followed by molecular speciation. A detailed, step-by-step diagnostic path was followed, as described in Appendix S1 1. The fungus isolated from the present case was identified as A. arundinis( Corda) Dyko & Sutton.
The cultured fungus( Fig. 1D) was subjected to drug susceptibility testing, with the Etest method( AB BIODISK, Solna, Sweden). Susceptibility assays were performed according to the Etest strip manufacturers’ instructions, with a 48-h incubation at 25 ° C( Appendix S1 1). In the absence of universally accepted guidelines specific for fungi, and especially Aspergillus, Arthrinium spp., interpretive criteria and quality control ranges for Aspergillus fumigatus, reported by the European Committee on Antimicrobial Susceptibility Testing were employed( 1). The tested fungus was found to be resistant to fluconazole( 32 μg / ml), anidulafungin( 2 μg / ml), caspofungin( 4 μg / ml); amphotericin B( 2 μg / ml) and 5-fluorocytosine(> 32 μg / ml), but susceptible to itraconazole( 0.125 μg / ml), voriconazole( 0.25 μg / ml) and posaconazole( 0.016 μg / ml).
Although terbinafine is commonly used for the treatment of onychomycosis, it was not considered in the present case, since no gradient strips are available for this drug, and thus its MIC value could not easily be established. Given the in vitro low MIC of itraconazole, its lipophilicity, high affinity for keratinizing tissues, and the high concentration that the drug reaches in the nails and maintains long after discontinuation of therapy( 2), it was used to treat the present case. The drug was given to the patient doi: 10.2340 / 00015555-2673 Acta Derm Venereol 2017; 97: 860 – 861
This is an open access article under the CC BY-NC license. www. medicaljournals. se / acta Journal Compilation © 2017 Acta Dermato-Venereologica.