Subcutaneous phaeohyphomycosis

Combination therapy with itraconazole and terbinafine for phaeohyphomycosis caused by Exophiala spinifera: A case report and literature review

Exophiala spinifera is a rare dematiaceous fungus causing cutaneous, subcutaneous and disseminated phaeohyphomycosis (PHM). Standard antifungal therapy for PHM is still uncertain. Here, we report a case of a Chinese male with PHM caused by E. spinifera, who received significant clinical improvement after the treatment with oral itraconazole and terbinafine. With the aim of evaluating the antifungal therapy for PHM caused by E. spinifera, a detailed review was performed.

Comparative Ecology of Capsular Exophiala Species Causing Disseminated Infection in Humans

Exophiala spinifera and Exophiala dermatitidis (Fungi: Chaetothyriales) are black yeast agents potentially causing disseminated infection in apparently healthy humans. They are the only Exophiala species producing extracellular polysaccharides around yeast cells. In order to gain understanding of eventual differences in intrinsic virulence of the species, their clinical profiles were compared and found to be different, suggesting pathogenic strategies rather than coincidental opportunism. Ecologically relevant factors were compared in a model set of strains of both species, and significant differences were found in clinical and environmental preferences, but virulence, tested in Galleria mellonella larvae, yielded nearly identical results. Virulence factors, i.e., melanin, capsule and muriform cells responded in opposite direction under hydrogen peroxide and temperature stress and thus were inconsistent with their hypothesized role in survival of phagocytosis. On the basis of physiological profiles, possible natural habitats of both species were extrapolated, which proved to be environmental rather than animal-associated. Using comparative genomic analyses we found differences in gene content related to lipid metabolism, cell wall modification and polysaccharide capsule production. Despite the fact that both species cause disseminated infections in apparently healthy humans, it is concluded that they are opportunists rather than pathogens.

Cutaneous and mucosal phaeohyphomycosis caused by Exophiala spinifera in a pregnant patient: case report and literature review

We report a case of mucocutaneous phaeohyphomycosis caused by Exophiala spinifera. Crusty plaques and nodules were major clinical features. Histological examination revealed brown yeast-like cells and hyphae. Mycological and molecular data identified E. spinifera as etiologic agent. Oral itraconazole was effective, which was in accordance with the results of in vitro susceptibility testing. We speculated that her pregnancy may play a role of risk factor in the infection by E. spinifera.

Chronic disfiguring facial lesions in an immunocompetent patient due to Exophiala spinifera: a case report and review of literature

Exophiala spinifera is a rare fungus causing chromoblastomycosis or different types of phaeohyphomycosis (cutaneous, subcutaneous, disseminated and cyst phaeohyphomycosis). We report a case of a young male with phaeohyphomycosis due to E. spinifera, who had multiple itchy painful papular lesions disfiguring his face for 4 years. His diagnosis was delayed and had received antibacterial and antileishmanial therapy elsewhere without any improvement. While he reported to our hospital, the histopathology of the biopsy collected from the lesion demonstrated acute on chronic inflammation with granuloma formation and darkly pigmented fungal elements. The isolate grown on culture was identified as E. spinifera on the basis of morphological characters. The identification of the isolate was further confirmed by sequencing of the ITS region of ribosomal DNA. After treatment with oral itraconazole, he had marked clinical improvement.

Multiple subcutaneous cysts due to Exophiala spinifera in an immunocompetent patient

Here we report a case of a 55-year-old Indian male presenting with multiple subcutaneous cysts, which developed from painful nodules at the dorsal right wrist joint. Subsequently a painful nodule appeared on the left knee joint. Cytological examination of the knee swelling revealed a suppurative inflammatory lesion consisting of neutrophils, lymphocytes, multinucleated giant cells and few fungal elements, without involvement of the overlying skin. Exophiala spinifera was cultured (CBS 125607) and its identity was confirmed by sequencing of the internal transcribed spacer (ITS rDNA). The cysts were excised surgically, without need of additional antifungal therapy. There was no relapse during one-year follow-up and the patient was cured successfully. In vitro antifungal susceptibility testing showed that posaconazole (0.063 μg/ml) and itraconazole (0.125 μg/ml) had the highest and caspofungin (4 μg/ml) and anidulafungin (2 μg/ml) the lowest activity against this isolate. However, their clinical effectiveness in the treatment of E. spinifera infections remains to be evaluated. In this case report, we have also compiled cases of human E. spinifera mycoses which have been reported so far.

Exophiala spinifera as a cause of cutaneous phaeohyphomycosis: case study and review of the literature

Exophiala spinifera has been reported as an agent of cutaneous disease 18 times in the literature. Clinical presentations of cutaneous lesions vary widely, including erythematous papules, verrucous plaques, and deep subcutaneous abscesses. The clinical distribution and course of disease are also variable, depending on the age and immune competency of the patient. Histologic appearance occurs in one of two patterns--phaeohyphomycosis or chromoblastomycosis. While E. spinifera appears to be susceptible to multiple antimicrobial agents in vitro, clinical experience with treatment modalities has been variable. Prior to the availability of sequencing methods, species identification was based on the histopathologic presentation in tissue and morphologic features of the fungus in culture. It is likely that E. spinifera cutaneous infections have been underreported due to its incorrect identification based on earlier methods. We report an additional case of E. spinifera phaeohyphomycosis, the first to be definitively identified by sequencing. In addition, we summarize the variable clinical, histopathologic, and morphologic features, as well as treatment responses described in previously reported cutaneous infections caused by E. spinifera.

Pheohyphomycosis caused by Exophiala spinifera: a rare occurrence

A 10-year-old immunocompetent boy presented with multiple, verrucous, disseminated pheohyphomycotic lesions caused by Exophiala spinifera. The patient was not responsive to combination antifungal therapy (itraconazole, terbinafine, fluconazole) and cryotherapy. As antifungal susceptibility is known to be variable for Exophiala spinifera, in vitro sensitivity testing is recommended before medical treatment. This article reviews, in brief, all cases documented so far in the English literature.

Phaeohyphomycosis caused by Exophiala spinifera in India

The second case of phaeohyphomycosis due to Exophiala spinifera in India has been diagnosed 46 years after the initial case. The present case involved a 12-year-old female patient with no known immunocompromising conditions. She presented with multiple verrucous, well-defined plaques encompassing phaeohyphomycotic lesions of varying sizes on her face, chest, arms and thighs. Lymph node involvement in dissemination was confirmed by demonstrating pigmented fungal elements in histopathology of the left axillary node. The infection responded positively to prolonged administration of itraconazole. The original case involved a young boy and was similarly disseminated but was more severe, with bone involvement, and had a fatal outcome. It is likely that other such cases have occurred in the intervening time but have not been reported.

Subcutaneous phaeohyphomycosis caused by Veronaea botryosa in the People's Republic of China

The second case of phaeohyphomycosis caused by Veronaea botryosa in China, in a 12-year-old boy from Jiangsu Province, is presented. Based on direct examination of the scrapings from crusted lesions; histologic examination of the biopsy tissue showing septate, phaeoid hyphal elements; and the culture exhibiting sympodial, conidiogenous cells producing predominantly two-celled, cylindric conidia, the etiologic agent was identified as V. botryosa.

Analyses of phagocytosis, evoked oxidative burst, and killing of black yeasts by human neutrophils: a tool for estimating their pathogenicity?

The pathogenicity of several dematiaceous yeasts that have, to date, rarely been isolated in humans remains unclear. Because professional phagocytes are prominent in lesions caused by dematiaceous fungi, we address this issue by comparing phagocytosis, evoked oxidative burst and killing by human neutrophils of different black yeasts in vitro. Whereas phagocytosis of all black yeasts tested and evoked oxidative burst yielded comparable results, in contrast, the degree of killing differed significantly after 5 h. Thereby, two groups could be identified; one in which strains are killed at high rates, for example, Hortaea werneckii (81 +/- 11.6%), Exophiala castellanii (96 +/- 8.6%), Phaeoannellomyces elegans (93 +/- 9.7%), Phaeococcomyces exophialae (87 +/- 8.7%), and the other in which strains are killed to a lesser degree, for example, Exophiala dermatitidis (ATCC 34100) (61 +/- 9.5%), E. dermatitidis (CBS 207.35) (66 +/- 7.5%), E. jeanselmei (50 +/- 10.5%), E. mesophila (63 +/- 11.6%), E. bergeri (63 +/- 9.1%), and E. spinifera (57 +/- 9.6%). Non-pigmented yeasts were killed at levels comparable with those at which the white mutant strain of E. dermatitidis (ATCC 44504) was killed (95 +/- 7.5%); the yeast strains tested were Candida albicans (DSM 11943) (95 +/- 4.0% killing) and Saccharomyces cerevisiae (DSM 1333) (95 +/- 10.3%). Comparison of killing rates with the observed pathogenicity of the melanized species suggests that low killing rates might indicate or even predict a high degree of invasiveness. Although previous experiments revealed that melanization conferred killing resistance on E. dermatitidis, the differences in killing rates of other dematious fungi suggest that melanization of the cell wall is in itself insufficient to confer virulence.

Relapsing cutaneous alternariosis in a kidney transplant recipient cured with liposomal amphotericin B

An immunosuppressed patient who presented with unusual clinical signs of cutaneous alternariosis, including papular, nodular and verrucous lesions of the forearms, is reported. In spite of continuous treatment with oral itraconazole for 6 months, a large, progressive, necrotic ulcer appeared on the patient's left leg. Liposomal amphotericin B was then administered (total dose, 750 mg) with excellent clinical results.

In vitro susceptibilities of 11 clinical isolates of Exophiala species to six antifungal drugs

The antifungal activities of miconazole, terbinafine, itraconazole, UR 9825, voriconazole and amphotericin B against 11 clinical isolates of Exophiala spp. were tested by the broth microdilution method. All drugs were very active against Exophiala spp.. The 90% minimal inhibitory concentration (MIC90) ranged from 0.125 to 1 microgram ml-1. Terbinafine was the most active drug against Exophiala spinifera, Exophiala dermatitidis and Exophiala castellanii and seems to be a promising agent in the treatment of infections caused by these fungi.

SCH 56592, amphotericin B, or itraconazole therapy of experimental murine cerebral phaeohyphomycosis due to Ramichloridium obovoideum ("Ramichloridium mackenziei")

Ramichloridium obovoideum ("Ramichloridium makenziei") is a rare cause of lethal cerebral phaeohyphomycosis. It has been, so far, geographically restricted to the Middle East. BALB/c mice were inoculated with two strains of R. obovoideum intracranially. Therapy with amphotericin B, itraconazole, or the investigational triazole SCH 56592 was conducted for 10 days. Half the mice were monitored for survival and half were killed for determination of the fungal load in brain tissue. Recipients of SCH 56592 had significantly prolonged survival and lower brain fungal burden, and this result was found for mice infected with both of the fungal strains tested. Itraconazole reduced the brain fungal load in mice infected with one strain but not the other, while amphotericin B had no effect on brain fungal concentrations. This study indicates a possible role of SCH 56592 in the treatment of the serious cerebral phaeohyphomycosis due to R. obovoideum.

Subcutaneous phaeohyphomycosis: overview and case report

Phaeohyphomycosis describes a heterogenous group of mycotic infections caused by pigmented fungi. Previously uncommon to the United States, the number of case reports in the American literature has steadily increased over the past two decades. This has been attributed to the ever increasing number of immunocompromised individuals as well as an influx of immigrants from areas where these opportunistic fungi are more commonly found. The authors present a generalized overview of phaeohyphomycosis as well as a more specific breakdown and case study involving subcutaneous phaeohyphomycosis.

Subcutaneous phaeohyphomycosis and nocardiosis in a kidney transplant patient

Phaeohyphomycosis and nocardiosis are uncommon infections that are more frequently reported in immunocompromised patients. To our knowledge, this is the first report of subcutaneous phaeohyphomycosis caused by Exophiala jeanselmei in association with systemic infection with Nocardia asteroides. The patient's phaeohyphomycosis responded to surgical excision and multi-drug therapy, and the patient underwent prolonged therapy with trimethoprim/sulfamethoxazole for treatment of the nocardiosis.