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A 42-year-old Vietnamese egg factory worker in Ishikawa prefecture, Japan, presented with itchy concentric erythema on the trunk and left calf. The lesions tested positive by direct potassium hydroxide examination, and two fungal strains were isolated. The isolates produced conidia abundantly and were morphologically indistinguishable from Trichophyton mentagrophytes/interdigitale, but were identified as Trichophyton indotineae by internal transcribed spacer sequence of ribosomal DNA. The lesions were refractory to treatment with topical luliconazole (LLCZ) cream for 4 weeks but subsided with oral itraconazole (ITCZ) 100 mg/day for 4 weeks in combination with topical lanoconazole (LCZ) cream. The lesions recurred 6 weeks after discontinuation of oral ITCZ, and an additional isolate was cultured. The minimum inhibitory concentrations of antimycotics for the isolate cultured at the first visit were: terbinafine (TBF) 0.03 μg/mL, ITCZ 0.015 μg/mL, LLCZ 0.0005 μg/mL, and LCZ 0.002 μg/mL. No TBF-resistant mutation in the amino acid sequence of squalene epoxidase, i.e., Leu 393 Ser/Phe or Phe 397 Leu, was detected in the isolate. The reason for recalcitrance in this case, despite the isolate's sensitivity to antimycotics, was unclear. Possible factors include insufficient use of the antimycotics, incomplete removal of abundantly produced conidia from the lesions, the patient's environment, and a language gap between the patient and physician hindering communication., (© 2024 Japanese Dermatological Association.)

A 67-year-old man had taken the janus kinase (JAK) inhibitor, tofacitinib, for ulcerative colitis. He was referred to our department for a refractory ulcer on his lower leg. We suspected vasculitis and performed skin biopsy. Histopathological examination showed multinucleated giant cells in the epidermis and fibrinoid degeneration of small vessels in the upper dermis. Varicella zoster virus (VZV) DNA was detected by polymerase chain reaction and we diagnosed the patient with atypical vasculitis-like herpes zoster. The patient was treated with oral valacyclovir, but the rash persisted and took 2 months to heal. Immunostaining using anti-VZV antibody was positive mainly in epidermal keratinocytes, but was also observed to be positive in cells in the dermis. We further performed RNA in situ hybridization using a VZV ORF9 mRNA probe and clearly showed that the distribution of VZV mRNA extended into the dermis, including the dermal vessel walls and the eccrine sweat glands as well as the epidermis. The internal administration of JAK inhibitors may induce regional widespread VZV infection including vessels and involved in the formation of prolonged vasculitis-like manifestation. RNA in situ hybridization can be a potent tool for detecting the spread of VZV infection in the skin., (© 2024 Japanese Dermatological Association.)

Over the past few years, cases of human papillomavirus (HPV) infection in nail Bowen's disease have been reported. This disease presents diagnostic challenges due to its similarity to nail malignant melanoma, particularly with respect to the clinical manifestation of black nail streaks. While skin biopsy is usually employed for diagnosis, it is an invasive procedure. We report the case of a 52-year-old healthy Japanese male with a pigmented streak on the nail of the fourth finger of his right hand, which had extended from the central to the lateral nail fold within 4 months. Dermoscopic examination revealed a dark-brown pigmented band with splinter microhemorrhage. Clinically, nail Bowen's disease was suspected. The lesion was excised in strips under local anesthesia. Histopathological examination revealed hyperkeratosis, parakeratosis, papillomatosis, and dyskeratotic cells with atypical nuclei irregularly arranged. Immunohistochemistry using anti-HPV L1 antibody detected HPV-positive cells in the upper epidermis and stratum corneum of the nail matrix. Mucosal high-risk HPV type 58 DNA was detected from brush cytology of the keratotic surface prior to surgery, which was confirmed in formalin-fixed, paraffin-embedded excised samples using polymerase chain reaction (PCR) and subsequent direct DNA sequencing. Our case highlights HPV type 58 as a potential causative agent of nail Bowen's disease and shows that brush cytology of the surface material prior to excision may be a useful and less invasive way for mucosal high-risk HPV detection. PCR analysis of the nail surface could serve as a supplementary diagnostic tool for nail Bowen's disease., (© 2024 Japanese Dermatological Association.)

An 85-year-old woman with no history of herpes zoster (HZ) presented with a primary lesion of erythema and blistering on her left thigh and a secondary similar lesion on her right chest which had appeared at 4 and 3 days before presentation, respectively. Tzanck smears for both lesions were positive, revealing multinucleated giant cells. Immunochromatography to detect varicella-zoster virus (VZV) antigen (DermaQuick®VZV) showed positive on the left thigh at initial onset but negative on the right chest at subsequent onset. The latter repeatedly tested negative for VZV by DermaQuick®VZV. A skin biopsy of the subsequent onset area revealed giant cells, and inclusion bodies were observed in the epidermis. Immunohistochemical staining with anti-VZV antibody and polymerase chain reaction to detect VZV DNA were positive. The patient was diagnosed with HZ duplex bilateralis and treated with acyclovir. The right thoracic region of the posterior part of the lesion became negative for DermaQuick®VZV. It is thought that expression of viral antigens was suppressed in the right thoracic region, i.e., the late-onset area., (© 2023 Japanese Dermatological Association.)

Fusarium species (spp.) is frequently found in soil and plant residues and on plant bodies in all climatic zones worldwide. Although there have been few reports of onychomycosis caused by Fusarium spp., it is characterized by drug sensitivity and other characteristics. Here, we report what may be the first case of onychomycosis caused by Fusarium lactis. We analyzed the mycology and characterized previously reported cases of onychomycosis caused by Fusarium spp. A 73-year-old otherwise healthy woman presented with discoloration and thickening of her right thumbnail with paronychia. Direct microscopy revealed unevenly swollen hyphae, and a Grocott-stained nail specimen showed septate hyphae. Based on the morphological features and gene analysis of fungus isolated from the nail, we diagnosed onychomycosis caused by F. lactis belonging to Fusarium fujikuroi species complex. Partial nail removal and topical application of 1% luliconazole solution resolved the condition in 6 months. Minimum inhibitory concentrations for isolated F. lactis showed high sensitivity to luliconazole but not itraconazole or terbinafine. The isolated F. lactis was temperature-sensitive. A search of the literature revealed 57 cases of onychomycosis caused by Fusarium spp. with delineated clinical characteristics. Since those cases were investigated using morphological and/or molecular methods, we analyzed them by species complex as well as species. Onychomycosis caused by Fusarium spp. is predominantly found on the big toe, with Fusarium solani species complex and Fusarium oxysporum species complex accounting for over 70% of cases. Infection of only one digit with paronychia is a characteristic clinical manifestation of onychomycosis caused by Fusarium spp. Since there has been an increase in instances of molecular determination of Fusarium spp., it is deemed necessary to clarify its clinical and fungal nature. Due to its characteristic drug sensitivity and temperature-sensitive nature, new treatments are expected to be developed., (© 2023 Japanese Dermatological Association.)

Warts, caused by human papillomavirus (HPV) infection, have various clinical presentations, making them difficult to differentiate from clavus, callus, and sometimes, squamous cell carcinoma. Although skin biopsies are the gold standard, a less-invasive method of examining these lesions is desired. Ninety patients with warts and related diseases, such as clavus and callus, were recruited to explore new differentiation methods using the surface of the warts. DNA was extracted from three types of specimens in each case: surface swab, shaved hyperkeratotic scale, and post-shaved surface swab. Total DNA was successfully extracted from these three specimens and was sufficient for subsequent HPV DNA detection. We analyzed samples for the HPV type and HPV viral load using polymerase chain reaction (PCR). Fifty-five cases were PCR-positive, and HPV1a, 2a, 4, 27, 57, and 65 were detected. The amount of HPV1a DNA produced was significantly greater than that of other HPV types. Regarding the correlation between the clinical diagnosis and HPV detection, the positive agreement rate was 90.9%, the negative agreement rate was 40.0%, and the overall agreement rate was 71.1%. Ten of the 21 cases clinically diagnosed as plantar warts were PCR-negative, especially in elderly patients. This suggests that it is difficult to distinguish plantar warts from clavus and callus in clinical practice. Although the amount of HPV DNA in the removed keratinization scale was highest for all HPV types, HPV detection by swabbing before and after shaving is also useful for follow-up as well as for differential diagnosis., (© 2023 Japanese Dermatological Association.)

Exophiala species cause chromoblastomycosis, mycetoma, and phaeohyphomycosis, which are occasionally fatally in immunocompromised patients. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) provides rapid and accurate examination of isolated bacteria and some fungal isolates, but the preparation method for filamentous fungi is complicated. In this study, 31 clinical isolates of Exophiala spp. in Japan were identified by MALDI-TOF MS with a library enriched by adding data. To simplify the sample preparation method, two modified methods were compared with the standard method for filamentous fungi. The agar cultivation sample preparation method reduced the time required for liquid culture and was considered suitable for clinical use. In 30 of 31 clinical isolates of Exophiala spp., the species identified by MALDI-TOF MS with the highest score matched the species identified by sequencing the internal transcribed spacer region. Exophiala dermatitidis, E. lecanii-corni, and E. oligosperma were identified above the genus level, while E. jeanselmei and E. xenobiotica were often not identified at the species level. The identification scores tended to be lower for less-registered strains in the in-house library. It is suggested that library enrichment and the modified preparation method may facilitate early diagnosis of rare fungal infections by Exophiala spp. in clinical laboratories using MALDI-TOF MS., (© 2023 Japanese Dermatological Association.)

Multilocus microsatellite typing was performed on 124 strains of Microsporum canis, which is the most prevalent causative fungus of zoonotic dermatophytosis, isolated in Japan between 1974 and 1981. The strains had been enclosed in glass ampoules by freeze dried process. Genotypes were detected by capillary electrophoresis targeted on six microsatellite regions, and 19 genotypes were found among these 124 strains. The most frequent genotype, which had been reported as genotype L in a previous study, comprised 56 of the 124 strains (45.2%), although genotype L was reported to comprise only six of 165 strains (3.6%) isolated between 2010 and 2017. A decrease in the prevalence of genotype L may have led to the retreat of M. canis infection in 1996 to 2006. On the other hand, genotype A, the second most predominant genotype in the aforementioned studies of strains isolated between 2010 and 2017, comprised just four of 124 strains (3.2%) in the present study. Thus, these studies reveal that prevalences of some major genotypes have changed over the last 40 years. Genotype consistency of strains was proven in all of 12 familial cases, each of which was infected with a single genotype. We emphasize the importance of fungal culture collection for further studies with new techniques in the future., (© 2022 Japanese Dermatological Association.)

Trichophyton tonsurans is the most prevalent fungus which causes dermatophytosis among contact sports players in Japan. We previously surveyed the epidemic of T. tonsurans in Japan from early 2000, and determined the genotypes of isolates by analysis of restriction enzyme fragment length polymorphisms in the non-transcription spacer (NTS) region of ribosomal RNA gene, which enabled discrimination of eight genotypes, namely NTS I to NTS VIII. In the present study, we performed genotyping of T. tonsurans isolated between 2016 and 2020, and investigated the trend of the epidemic and resistance of the pathogen to antibiotic terbinafine (TBF). Regardless of which contact sport they played, the genotype of all 123 strains of T. tonsurans isolated from athletes was NTS I. Genotypes NTS II and III, which were isolated in considerable numbers mainly from wrestlers between 2000 and 2015, were conspicuously absent. TBF susceptibility was screened in 237 T. tonsurans strains isolated between 2000 and 2020 with 28 of these further assessed for minimum inhibitory concentration of TBF and squalene epoxidase gene sequences. None of the strains showed TBF resistance. TBF may still be effective to control the epidemic of T. tonsurans., (© 2022 Japanese Dermatological Association.)

Restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA) had been used for molecular identification of Sporothrix spp., which is the causative fungi of sporotrichosis and the most prevalent deep-seated dermatomycosis. Also, mtDNA-RFLP had been used to investigate the molecular epidemiology of sporotrichosis. While the current standard for molecular diagnosis is performed by sequence analysis of the calmodulin gene (CAL), correspondence between the results from CAL and mtDNA is of diagnostic and epidemiological interest. Here, we investigated the correspondence between CAL and mtDNA used for molecular identification of Sporothrix globosa and S. schenckii, which are two major species. We also investigated and propose molecular markers suitable to describe the epidemiology of S. globosa, which is considered as a species with few intraspecific polymorphisms. Eighty-seven strains morphologically identified as S. schenckii sensu lato were investigated. They were identified as group A (17 types, 17 strains) or B (14 types, 70 strains) by mtDNA-RFLP. Partial sequences of CAL, internal transcribed spacer, and spacer between atp9 and cox2 genes of mtDNA of these strains were determined. All group A strains corresponded to S. schenckii, and group B to S. globosa. The sequences of the amplicons targeted on the spacer region in mtDNA of S. globosa ranged 510-515 bp in length and exhibited 10 molecular variations, whereas CAL indicated seven molecular variations. In conclusion, most of the S. schenckii sensu lato strains isolated from Japanese sporotrichosis patients were confirmed as S. globosa, because group B, which comprised the majority of strains, matched perfectly with S. globosa by the CAL sequencing study. We proposed sequence variations in the spacer between atp9 and cox2 genes of mtDNA as a suitable molecular epidemiological marker for S. globosa., (© 2021 The Authors. The Journal of Dermatology published by John Wiley & Sons Australia, Ltd on behalf of Japanese Dermatological Association.)

Trichophyton tonsurans is a major causative fungus of human dermatophytosis, which has been isolated from contact sport players in Japan. The microbiome in the scalp of judoists with or without T. tonsurans infection was analyzed to investigate the correlation between T. tonsurans infection and microbiome profile. Among 30 members of the same judo team in a high school, samples were collected by scrubbing their scalp with shampoo hairbrushes; then, DNA was extracted directly from the obtained scales. Twenty-seven datasets were subjects for microbiome analysis and T. tonsurans was detected in six members (no T. tonsurans-positive participants had scalp lesions). Regarding the fungal microbiome, Cyphellophora were more abundant in the T. tonsurans-positive group (TP) than T. tonsurans-negative group (TN) (P < 0.05). Regarding the Malassezia microbiome, Malassezia caprae were more abundant in TP than TN (P < 0.01). Regarding the bacterial microbiome, Lactococcus, Actinobacillus, Beijerinckiaceae and Xanthomonas were more abundant in TP than TN (P < 0.05). Also, the Shannon diversity index revealed no significant diversity between TP and TN, and 3-D principal coordinate analysis revealed no clear separation between TP and TN. There was practically no difference in microbiome between TP and TN, indicating that T. tonsurans could colonize humans regardless of their original microbiome. T. tonsurans coexisted with other fungi and bacteria without affecting species diversity in asymptomatic carriers. To our knowledge, this is the first investigation of the correlation between T. tonsurans infection and microbiome profile., (© 2020 Japanese Dermatological Association.)

Cutaneous cryptococcosis is classified as localized cutaneous cryptococcosis and cutaneous manifestations of disseminated cryptococcosis. The former presents as lesions, confined to isolated parts of the skin, which are neither systemically disseminated nor associated with cryptococcal fungemia or antigenemia. The latter presents as lesions through dissemination of Cryptococcus from visceral organs such as the lungs, with most cases being immunosuppressed hosts. We report the case of an immunocompetent elderly long-term pigeon fancier who presented with disseminated cutaneous cryptococcosis caused by Cryptococcus neoformans. Although the patient had been at risk of inhaling the pathogen by keeping pigeons for many years, and had been treated with topical steroids for a localized nodular lesion, the cause of development of multiple skin lesions could not be determined. The patient paradoxically showed no pulmonary or central nervous system symptoms, fungemia or glucuronoxylomannan antigenemia. Treatment with oral itraconazole 200 mg/day was not effective, but combination therapy of 5-fluorocytosine 200 mg/kg per day and fluconazole 100 mg/day resolved the disease., (© 2020 Japanese Dermatological Association.)

We report a case of kerion celsi due to Trichophyton tonsurans. An 18-year-old male student judo practitioner had alopecic patches, black dots and subcutaneous abscesses on the right temporal region. The damaged hair represented endothrix infection with T. tonsurans, as assessed by mycological examinations. He was treated with oral itraconazole without any therapeutic effect, followed by terbinafine with good effect. A skin biopsy showed neutrophil, lymphocyte and histiocyte infiltration into the dermis and subcutaneous tissue with abscesses around a number of dilated hair follicles. Immunostaining showed that the expression level of human β-defensin 2 (HBD-2) was decreased in the epidermis of the alopecic and adjacent skin. Because interleukin (IL)-17A generally induces HBD-2 production by epidermal keratinocytes, we also immunohistochemically investigated IL-17A expression. Unexpectedly, many IL-17A-bearing cells were found around destructed hair follicles, indicating that IL-17A expression was not attenuated, but rather increased in the skin lesion. Our case suggests that IL-17A-upregulated antimicrobial peptide expression is disordered in kerion celsi, and severe inflammation with IL-17A may cause tissue damage and resultant scar., (© 2019 Japanese Dermatological Association.)

Favus is a type of dermatophytosis known to produce yellow scutula around hair follicles. Most cases of this disease worldwide are infections of Trichophyton schoenleinii. Favus has rarely been reported in Japan throughout the last four decades, and T. schoenleinii has not been clinically isolated in any case during the period. Here, we report a case of favus of vellus hair observed in a 63-year-old Japanese woman. Fungal culture showed negative; however, we detected fungal elements in the crust and hair bulbs by Grocott staining. Pathogenic fungi were identified as T. schoenleinii by polymerase chain reaction-based DNA sequencing, targeting the internal transcribed spacer regions of the rRNA gene using the formalin-fixed, paraffin-embedded tissue sample. She was successfully treated with p.o. administration of terbinafine and topical application of luliconazole cream., (© 2019 Japanese Dermatological Association.)

Primary cutaneous aspergillosis is a rare, life-threatening fungal infection in premature infants. We report a case of primary cutaneous aspergillosis caused by Aspergillus tamarii in an extremely low birthweight infant. The infant was delivered by cesarean section with complications from an intrauterine infection, brain intraventricular hemorrhage, tension pneumothorax and cardiac tamponade. On the 12th day of life, he developed erythematous maceration with erosion on his back. Septate hyphae were detected on two occasions from specimens of the skin lesion. The manifestations of the colony and slide culture showed the characteristics of A. tamarii. The nucleotide sequences of internal transcribed spacer regions of the ribosomal RNA gene, partial sequences of β-tubulin and calmodulin gene were compatible with those of A. tamarii. Of the known Aspergillus species, Aspergillus fumigatus and Aspergillus flavus have been reported in previous studies as the major causative agents in primary cutaneous aspergillosis, whereas human infection by A. tamarii is rare. We consider that A. tamarii is important as an unusual opportunistic human pathogen among premature infants., (© 2018 Japanese Dermatological Association.)

Fonsecaea pedrosoi sensu lato is a major causative agent of dematiaceous fungal infection in Japan. Recent sequence analysis of the internal transcribed spacer (ITS) regions of the ribosomal RNA gene has shown that this species can be separated into three species: F. pedrosoi sensu stricto, F. monophora and F. nubica. The cell walls of dematiaceous fungi including the genus Fonsecaea contain melanin, which is important for their virulence. Polyketide synthase (PKS1) is an enzyme required for melanin synthesis. This study analyzed the phylogeny of strains of F. pedrosoi sensu lato isolated in Japan by sequencing the PKS1 gene and ITS regions and identifying molecular polymorphism. Sixty strains morphologically identified as F. pedrosoi isolated worldwide, including 37 strains isolated in Japan, were analyzed. ITS regions of the ribosomal RNA gene and part of the PKS1 gene region were amplified, yielding sequences of approximately 600 and 450 bp, respectively. Polymerase chain reaction products were sequenced, and cluster analysis was performed. The proposed phylogenetic tree based on PKS1 sequences closely matched that based on the ITS regions. Sequencing of both regions showed that the isolates from Japan belonged to the clade of F. monophora. Molecular variations of these Japanese strains were evaluated by assessing both ITS and PKS1 sequences. The 37 isolates could be divided into at least seven molecular subtypes. The combination of these two molecular markers provides a most robust method for intraspecies subtyping and further epidemiological study of F. monophora., (© 2016 Japanese Dermatological Association.)

Dermatophytosis is a very common skin disorder and the most prevalent infectious disease treated by dermatologists. Recent developments in molecular techniques have markedly changed methods of identifying dermatophytes, with these methods showing intraspecies polymorphisms in some molecular markers. Intraspecies subtyping and strain differentiation have made possible the tracking of infections, the identification of common sources of infections and recurrence or reinfection after treatment. This review describes methods of intraspecies differentiation using mitochondrial DNA, random amplification of polymorphic DNA, non-transcribed spacer regions of ribosomal RNA genes and microsatellite markers, as well as their usefulness and limitations., (© 2015 Japanese Dermatological Association.)

We describe a case of cutaneous phaeohyphomycosis in a 61-year-old man receiving re-dialysis treatment for renal failure of a transplanted kidney. He was immunocompromised with steroid and cyclosporin A at onset of an asymptomatic abscess on his right forearm. The abscess arose at the site of a skin injury approximately 1 year prior. Grayish molds isolated from the lesion were morphologically compatible with Phaeoacremonium sp. but nucleotide sequence data of internal transcribed spacer regions of ribosomal RNA gene, actin and β-tubulin genes were unlike those of any described species. He was successfully treated with a total of 3 weeks of liposomal amphotericin B, but died of pneumonia approximately 3 months after cure of phaeohyphomycosis., (© 2014 Japanese Dermatological Association.)

Trichophyton tonsurans is known to be the causative agent of a worldwide epidemic of dermatophytoses among contact sports practitioners, and is spreading among the general population of Japan. Prompt and simple identification of T. tonsurans in diagnostic laboratories is crucial to control infection. The present study evaluated the availability of observation of chlamydospore-like structures grown in culture media as a characteristic for identification of T. tonsurans. Twenty-five strains of T. tonsurans and five strains each of Trichophyton verrucosum, Trichophyton rubrum and Trichophyton mentagrophytes were inoculated on Mycosel agar plates and inoculated Petri dishes were observed by light microscopy from the reverse side. Twenty-three of 25 T. tonsurans strains showed chlamydospore-like structures within 5 days, and all strains at day 8. The numbers of chlamydospore-like structures were very abundant in most strains. The majority of strains of other species showed no chlamydospore-like structures, or very few when present. Positive for chlamydospore-like structures among 15 strains other than T. tonsurans was one strain at day 5 and six strains at day 8. As for the identification of T. tonsurans, presence of chlamydospore-like structures showed 92.0% sensitivity (23/25) and 93.3% specificity (14/15) at day 5, and 100% sensitivity (25/25) and 60.0% specificity (9/15) at day 8. Electron microscopic findings suggest chlamydospore-like structures are not true chlamydospores but are produced by inflation of actively growing hyphae by developing vacuoles in cells. In conclusion, observation of development of chlamydospore-like structures in culture media is the simplest method for identification of T. tonsurans., (© 2013 Japanese Dermatological Association.)

Sporotix schenckii is a pathogenic fungus that causes human and animal sporotrichosis, and based on morphology of the sessile conidia and molecular analysis, it was recently recognized as a species complex comprising at least the following six sibling species: S. albicans, S. brasiliensis, S. globosa, S. luriei, S. mexicana and S. schenckii. However, apart from S. schenckii sensu strict, only S. brasiliensis, S. globosa and S. luriei are associated with human and animal infection. S. globosa has been most commonly isolated in Asia, Europe and the USA; therefore, molecular epidemiological study for S. globosa is important in relation to human sporotrichosis in Japan. To the best of our knowledge, this is the first study to determine the mating type 1-2 (MAT1-2) gene of Sporothrix schenckii with the aim of understanding the taxonomy of the genus Sporothrix. The MAT1-2 gene (1618 bp) encodes a protein sequence of 198 amino acids. Reverse transcription polymerase chain reaction analysis also detected MAT1-2 gene mRNA expression in all of the S. schenckii strains examined, indicating that this gene is expressed in S. schenckii cells. Phylogenetic analysis of the MAT1-2 gene fragments of Ophiostoma himal-ulmi, O. novo-ulmi, O. ulmi and S. schenckii indicated that these isolates could be classified into four clusters. MAT1-1 gene-specific polymerase chain reaction was positive in 15 isolates, but negative in four human isolates and one feline isolate., (© 2013 Japanese Dermatological Association.)

A 90-year-old Japanese woman, taking prednisolone (5-10 mg/day) for polyarthritis, presented to our hospital with multiple subcutaneous lesions on her left arm in 2009. Her history included excision of a phaeomycotic cyst on the left middle finger in 2007. There were three subcutaneous nodules approximately 15 mm in diameter around her left wrist and a large soft cystic lesion measuring 80 mm × 60 mm on her left elbow. A granuloma with neutrophilic infiltration was detected in the deep dermis of a biopsy specimen. Chains composed of round brown cells and short pseudomycelia were found in the granuloma. Fungal cultures from the samples confirmed Exophiala sp. to be the causative agent. Treatment with terbinafine and local hyperthermia seemed effective as all the lesions tended to subside. However, the patient died due to pneumonia approximately 1 month after commencement of therapy., (© 2013 Japanese Dermatological Association.)

The complete sequences of mitochondrial DNA (mtDNA) from two strains of different genotypes, American Type Culture Collection 10268 of mtDNA type 1 and KMU2025 of mtDNA type 4, were determined. These are circular molecules, 27 125 and 26 095 bp in length, respectively. The greatest difference between the two strains was found in the region encompassed by atp9 and cox2 genes, which was amplified with polymerase chain reaction (PCR) and used for preliminary restriction fragment length polymorphism (RFLP) analysis. Eight isolates of five mtDNA types were used and RFLP patterns obtained with the restriction enzyme AseI showed that this method seems to have greater discrimination power than the other PCR-RFLP typing method using internal transcribed spacer regions of nuclear DNA., (© 2011 Japanese Dermatological Association.)

Detecting intraspecies polymorphisms in fungi causing dermatophytoses is important in elucidating routes of infection and determining whether Tinea recurrence is caused by exacerbation or re-infection. In fungi, the non-transcribed spacer region (NTS) of the ribosomal RNA gene shows the greatest accumulation of base sequence mutations. We therefore assessed NTS sequences in 64 clinical isolates of Trichophyton mentagrophytes var. interdigitale, the second most common species of dermatophytes in Japan. These isolates were among the clinical isolates of dermatophytes in the Department of Dermatology, Kanazawa Medical University Hospital in 2006 and were obtained by morphological and molecular biological identification methods. DNA was extracted from each isolate, as well as from one isolate maintained in our department, to detect length polymorphisms at each of three variable loci, TmiS0, TmiS1 and TmiS2, of the NTS for subtyping. We observed seven patterns for TmiS0, six patterns for TmiS1 and three patterns for TmiS2. The combinations of these patterns enabled us to classify the 65 isolates into 15 types. The most prevalent, constituted 46% (30/65) of all isolates. Eleven types were new combinations, whereas the other four were previously described. These results suggest that this method may be used to determine the molecular epidemiology of T. mentagrophytes var. interdigitale in Japan, because it generated results rapidly and in a sensitive manner.