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The British Journal of Dermatology Jul 2023
Topics: Humans; Onychomycosis; Nails; Arthrodermataceae; Antifungal Agents; Itraconazole; Foot Dermatoses
PubMed: 37418645
DOI: 10.1093/bjd/ljad169 -
Mycopathologia Oct 2023Tinea capitis is a cutaneous infection of dermatophytes and predominant in children. It is one of common infectious diseases of children in Xinjiang, particularly in the...
Tinea capitis is a cutaneous infection of dermatophytes and predominant in children. It is one of common infectious diseases of children in Xinjiang, particularly in the southern Xinjiang. The aim of this study is to analyze the clinical and mycological characteristics of patients with tinea capitis in Xinjiang China. Medical records from 2010 to 2021, Mycology Laboratory Department of Dermatology in the First Affiliated Hospital of Xinjiang Medical University, retrospectively investigated the clinical and mycological characteristics of 198 patients with tinea capitis. Hairs have been obtained for fungal examination, and analysis with 20% KOH and Fungus Fluorescence Staining Solution has been conducted. Identification of fungi was using of morphological and molecular biological methods. Among total number of 198 patients, 189 (96%) were children with tinea capitis, of which 119 (63%) were male and 70 (37%) were female; 9 (4%) were adult patients with tinea capitis, of which 7 were female and 2 were male. Preschool children between the ages of 3 and 5 years had the highest distribution (54%), followed by those between the ages of 6 and 12 years (33%), the ages under 2 years (11%) and the ages of 13-15 years (2%) respectively. Among all patients, 135 (68.18%) were Uygur, 53 (26.77%) were Han, 5 (2.53%) were Kazak, 3 (1.52%) were Hui, 1 (0.5%) was Mongolian and nationality information of 1 patient (0.5%) is unknown. The indentification results of the isolates showed that 195 (98%) patients had single-species infections and 3 (2%) patients had double mixed infections. Among single-species infection patients, Microsporum canis (n = 82, 42.05%), Microsporum ferrugineum (n = 56, 28.72%) and Trichophyton mentagrophytes (n = 22, 11.28%) were the most prevalent species. Other dermatophytes included Trichophyton tonsurans (n = 12, 6.15%), Trichophyton violaceum (n = 10, 5.13%), Trichophyton schoenleinii (n = 9, 4.62%) and Trichophyton verrucosum (n = 4, 2.05%). Among 3 cases of mixed infections, 1 was M. canis + T. tonsurans (n = 1), and the other 2 were M.canis + T.mentagrophytes (n = 2). In conclusion, the majority of tinea capitis patients in Xinjiang, China are Uygur male children aged 3-5 years. M. canis was the most prevalent species causing tinea capitis in Xinjiang. These results provide useful information for the treatment and prevention of tinea capitis.
Topics: Adult; Child, Preschool; Humans; Male; Female; Child; Retrospective Studies; Coinfection; Tinea Capitis; Microsporum; China; Trichophyton
PubMed: 37012555
DOI: 10.1007/s11046-022-00702-0 -
Mycoses Jan 2024A growing body of literature has marked the emergence and spread of antifungal resistance among species of Trichophyton, the most prevalent cause of toenail and... (Review)
Review
A growing body of literature has marked the emergence and spread of antifungal resistance among species of Trichophyton, the most prevalent cause of toenail and fingernail onychomycosis in the United States and Europe. We review published data on rates of oral antifungal resistance among Trichophyton species; causes of antifungal resistance and methods to counteract it; and in vitro data on the role of topical antifungals in the treatment of onychomycosis. Antifungal resistance among species of Trichophyton against terbinafine and itraconazole-the two most common oral treatments for onychomycosis and other superficial fungal infections caused by dermatophytes-has been detected around the globe. Fungal adaptations, patient characteristics (e.g., immunocompromised status; drug-drug interactions), and empirical diagnostic and treatment patterns may contribute to reduced antifungal efficacy and the development of antifungal resistance. Antifungal stewardship efforts aim to ensure proper antifungal use to limit antifungal resistance and improve clinical outcomes. In the treatment of onychomycosis, critical aspects of antifungal stewardship include proper identification of the fungal infection prior to initiation of treatment and improvements in physician and patient education. Topical ciclopirox, efinaconazole and tavaborole, delivered either alone or in combination with oral antifungals, have demonstrated efficacy in vitro against susceptible and/or resistant isolates of Trichophyton species, with low potential for development of antifungal resistance. Additional real-world long-term data are needed to monitor global rates of antifungal resistance and assess the efficacy of oral and topical antifungals, alone or in combination, in counteracting antifungal resistance in the treatment of onychomycosis.
Topics: Humans; Antifungal Agents; Onychomycosis; Terbinafine; Itraconazole; Trichophyton; Administration, Topical
PubMed: 38214375
DOI: 10.1111/myc.13683 -
Journal of the European Academy of... Oct 2023Fungal infections are the most frequent dermatoses. The gold standard treatment for dermatophytosis is the squalene epoxidase (SQLE) inhibitor terbinafine. Pathogenic...
BACKGROUND
Fungal infections are the most frequent dermatoses. The gold standard treatment for dermatophytosis is the squalene epoxidase (SQLE) inhibitor terbinafine. Pathogenic dermatophytes resistant to terbinafine are an emerging global threat. Here, we determine the proportion of resistant fungal skin infections, analyse the molecular mechanisms of terbinafine resistance, and validate a method for its reliable rapid identification.
METHODS
Between 2013 and 2021, we screened 5634 consecutively isolated Trichophyton for antifungal resistance determined by hyphal growth on Sabouraud dextrose agar medium containing 0.2 μg/mL terbinafine. All Trichophyton isolates with preserved growth capacity in the presence of terbinafine underwent SQLE sequencing. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method.
RESULTS
Over an 8-year period, the proportion of fungal skin infections resistant to terbinafine increased from 0.63% in 2013 to 1.3% in 2021. Our routine phenotypic in vitro screening analysis identified 0.83% (n = 47/5634) of Trichophyton strains with in vitro terbinafine resistance. Molecular screening detected a mutation in the SQLE in all cases. Mutations L393F, L393S, F397L, F397I, F397V, Q408K, F415I, F415S, F415V, H440Y, or A A G deletion were detected in Trichophyton rubrum. Mutations L393F and F397L were the most frequent. In contrast, all mutations detected in T. mentagrophytes/T. interdigitale complex strains were F397L, except for one strain with L393S. All 47 strains featured significantly higher MICs than terbinafine-sensitive controls. The mutation-related range of MICs varied between 0.004 and 16.0 μg/mL, with MIC as low as 0.015 μg/mL conferring clinical resistance to standard terbinafine dosing.
CONCLUSIONS
Based on our data, we propose MIC of 0.015 μg/mL as a minimum breakpoint for predicting clinically relevant terbinafine treatment failure to standard oral dosing for dermatophyte infections. We further propose growth on Sabouraud dextrose agar medium containing 0.2 μg/mL terbinafine and SQLE sequencing as fungal sporulation-independent methods for rapid and reliable detection of terbinafine resistance.
Topics: Humans; Terbinafine; Antifungal Agents; Agar; Tinea; Arthrodermataceae; Trichophyton; Skin Diseases, Infectious; Microbial Sensitivity Tests; Squalene Monooxygenase; Glucose
PubMed: 37319111
DOI: 10.1111/jdv.19253 -
Mycoses Nov 2023Onychomycosis is common among immunosuppressed individuals. Renal transplant recipients (RTR) and lupus nephritis (LN) patients are submitted to corticosteroid and other...
UNLABELLED
Onychomycosis is common among immunosuppressed individuals. Renal transplant recipients (RTR) and lupus nephritis (LN) patients are submitted to corticosteroid and other immunosuppressive therapy; and diabetes mellitus (DM) patients are intrinsically immunocompromised.
OBJECTIVES
The aim of this study was to characterise and identify fungal infections on the nails (feet and hands) in immunocompromised patients.
METHODS
The clinical material, nail scales (foot and/or hand), was collected from 47 RTR, 66 LN, 67 DM, and 78 immunocompetent individuals (control group). Phenotypic and molecular analyses were performed.
RESULTS
A total of 258 patients were examined. There was a female predominance, except in the RTR. The average age was 52 years old. Lateral distal subungual onychomycosis (OSDL) (75.2%), mainly affecting the hallux nail, was frequent. The predominance of dermatophyte on toenails and Candida species on fingernails was statistically significant. A higher frequency of fingernail involvement in LN and DM, and for LN, the difference was significant (p = .0456). Infections by Candida spp. were more frequent in DM. Using molecular methods, 87.2% of diagnoses were confirmed, identifying fungal agents at the species level. Dermatophytes, Trichophyton rubrum and Trichophyton interdigitale and the species of Candida, C. parapsilosis and C. albicans, were the most frequent fungal agents.
CONCLUSIONS
Molecular techniques (sequencing of ITS regions of rDNA) offer greater accuracy, although there is no difference, regarding the detection. Clinical presentation and fungal species may differ somewhat from the general population. Immunosuppression did not increase fungal detection positivity.
Topics: Humans; Female; Middle Aged; Male; Onychomycosis; Nails; Candida albicans; Candida; Immunocompromised Host; Candida parapsilosis
PubMed: 37488648
DOI: 10.1111/myc.13634 -
Mycoses Apr 2024Onychomycosis is a chronic nail disorder commonly seen by healthcare providers; toenail involvement in particular presents a treatment challenge. (Review)
Review
BACKGROUND
Onychomycosis is a chronic nail disorder commonly seen by healthcare providers; toenail involvement in particular presents a treatment challenge.
OBJECTIVE
To provide an updated estimate on the prevalence of toenail onychomycosis.
METHODS
We conducted a literature search using PubMed, Embase and Web of Science. Studies reporting mycology-confirmed diagnoses were included and stratified into (a) populations-based studies, and studies that included (b) clinically un-suspected and (c) clinically suspected patients.
RESULTS
A total of 108 studies were included. Based on studies that examined clinically un-suspected patients (i.e., with or without clinical features suggestive of onychomycosis), the pooled prevalence rate of toenail onychomycosis caused by dermatophytes was 4% (95% CI: 3-5) among the general population; special populations with a heightened risk include knee osteoarthritis patients (RR: 14.6 [95% CI: 13.0-16.5]), chronic venous disease patients (RR: 5.6 [95% CI: 3.7-8.1]), renal transplant patients (RR: 4.7 [95% CI: 3.3-6.5]), geriatric patients (RR: 4.7 [95% CI: 4.4-4.9]), HIV-positive patients (RR: 3.7 [95% CI: 2.9-4.7]), lupus erythematosus patients (RR: 3.1 [95% CI: 1.2-6.3]), diabetic patients (RR: 2.8 [95% CI: 2.4-3.3]) and hemodialysis patients (RR: 2.8 [95% CI: 1.9-4.0]). The prevalence of onychomycosis in clinically suspected patients was significantly higher likely due to sampling bias. A high degree of variability was found in a limited number of population-based studies indicating that certain pockets of the population may be more predisposed to onychomycosis. The diagnosis of non-dermatophyte mould onychomycosis requires repeat sampling to rule out contaminants or commensal organisms; a significant difference was found between studies that performed single sampling versus repeat sampling. The advent of PCR diagnosis results in improved detection rates for dermatophytes compared to culture.
CONCLUSION
Onychomycosis is an underrecognized healthcare burden. Further population-based studies using standardized PCR methods are warranted.
Topics: Humans; Aged; Onychomycosis; Prevalence; Nails; Diabetes Mellitus; Kidney Transplantation
PubMed: 38606891
DOI: 10.1111/myc.13725 -
Journal of the European Academy of... Mar 2024Nondermatophyte moulds (NDMs) are widely distributed and can be detected in association with mycotic nails; however, sometimes it can be challenging to establish the... (Review)
Review
Nondermatophyte moulds (NDMs) are widely distributed and can be detected in association with mycotic nails; however, sometimes it can be challenging to establish the role of NDMs in the pathogenesis of onychomycosis (i.e. causative vs. contaminant). In studies where the ongoing invasive presence of NDMs is confirmed through repeat cultures, the global prevalence of NDMs in onychomycosis patients is estimated at 6.9% with the 3 most common genus being: Aspergillus, Scopulariopsis and Fusarium. NDM onychomycosis can, in many cases, appear clinically indistinguishable from dermatophyte onychomycosis. Clinical features suggestive of NDMs include proximal subungual onychomycosis with paronychia associated with Aspergillus spp., Fusarium spp. and Scopulariopsis brevicaulis, as well as superficial white onychomycosis in a deep and diffused pattern associated with Aspergillus and Fusarium. Longitudinal streaks seen in patients with distal and lateral onychomycosis may serve as an additional indicator. For diagnosis, light microscopic examination should demonstrate fungal filaments consistent with an NDM with at least two independent isolations in the absence of a dermatophyte; the advent of molecular testing combined with histological assessment may serve as an alternative with improved sensitivity and turnover time. In most instances, antifungal susceptibility testing has limited value. Information on effective treatments for NDM onychomycosis is relatively scarce, unlike the situation in the study of dermatophyte onychomycosis. Terbinafine and itraconazole therapy (continuous and pulsed) appear effective to varying extents for treating onychomycosis caused by Aspergillus, Fusarium or Scopulariopsis. There is scant literature on oral treatments for Neoscytalidium.
Topics: Humans; Onychomycosis; Terbinafine; Itraconazole; Treatment Outcome; Paronychia
PubMed: 38010049
DOI: 10.1111/jdv.19644 -
Pediatric Dermatology 2023
Topics: Infant; Humans; Paronychia; Candidiasis, Cutaneous
PubMed: 36958306
DOI: 10.1111/pde.15290 -
Mycoses Mar 2024Dermatophytosis has assumed epidemic proportions with rising resistance, recalcitrance and recurrence, especially in tropical regions. While various factors contribute...
BACKGROUND
Dermatophytosis has assumed epidemic proportions with rising resistance, recalcitrance and recurrence, especially in tropical regions. While various factors contribute to high prevalence worldwide, yet little is known about the interactions between host defence mechanisms and dermatophytes, particularly in chronic and recalcitrant dermatophytosis.
OBJECTIVES
We aimed to compare the population of various immune cells in specimens of chronic recurrent dermatophytosis and those with acute superficial dermatophytosis.
METHODS
We investigated the density of various immune cells-Langerhans cells (CD1a+), macrophages (CD68+), dermal dendrocytes (Factor XIIIa+) in the skin of chronic dermatophytosis patients and those with successfully resolved lesions (controls).
RESULTS
Langerhans cells were significantly decreased in the epidermis of patients, both in affected and unaffected areas in comparison with controls. In the dermis, however, no differences in the density of immune cells (macrophages and fibroblasts) were observed.
LIMITATIONS
The limited sample size and immune cells evaluated could be expanded further in future research.
CONCLUSION
These results indicate that the decreased number of Langerhans cells could be a potential risk factor for the development of chronic and recurrent dermatophytosis.
Topics: Humans; Skin; Langerhans Cells; Epidermis; Factor XIIIa; Tinea
PubMed: 38488272
DOI: 10.1111/myc.13714 -
Emerging Microbes & Infections Dec 2023Dermatophytic pseudomycetoma is a rare invasive infection, involving both immunocompetent and immunocompromised individuals. Since the discovery of inherited immune...
Dermatophytic pseudomycetoma is a rare invasive infection, involving both immunocompetent and immunocompromised individuals. Since the discovery of inherited immune disorders such as the impairment of gene, extended dermatophyte infections are mostly ascribed to any of these host factors. This study is to present and explore the potential causes in a fatal dermatophytic pseudomycetoma patient. We present a chronic and deep pseudomycetoma caused by the common dermatophyte which ultimately led to the death of the patient. Mycological examination, genetic studies and host immune responses against fungi were performed to explore the potential factors. The patient had decreased lymphocyte counts with significantly reduced CD4 T cells, although all currently known genetic parameters proved to be normal. Through functional studies, we demonstrated that peripheral blood mononuclear cells from the patient showed severe impairment of adaptive cytokine production upon fungus-specific stimulation, whereas innate immune responses were partially defective. This is, to our knowledge, the first report of fatal dermatophytic pseudomycetoma in a patient with non-HIV CD4 lymphocytopenia, which highlights the importance of screening for immune deficiencies in patients with deep dermatophytosis.
Topics: Humans; Dermatomycoses; Mycetoma; Female; Middle Aged; Microsporum; Fatal Outcome; Caspase 9; Receptors, Interleukin-7; Mutation; Rare Diseases; CD4 Lymphocyte Count; Immunity, Innate
PubMed: 37128909
DOI: 10.1080/22221751.2023.2208685