Search Results (117)

Dermatophytosis is commonly assessed using potassium hydroxide (KOH) microscopy, yet accurate recognition of fungal hyphae is hindered by preparation-related artifacts, heterogeneous keratin clearance, and notable inter-observer variability. This study presents a transformer-based object detection framework using the RT-DETR architecture for precise, query-driven localisation of fungal structures in high-resolution KOH images. A dataset of 2540 routinely acquired microscopy images was manually annotated using a multi-class strategy that explicitly distinguishes fungal elements from confounding artifacts, enabling the model to actively suppress false detections arising from visually similar mimics. To assess architectural trade-offs, RT-DETR was benchmarked against two CNN-based detectors (YOLOv11 and Faster R-CNN) under identical training and inference conditions. Five-fold stratified cross-validation was performed, and each fold-level model was evaluated on the same independent held-out test set (n = 254). Across the five evaluations, RT-DETR achieved a mean AP@0.50 of $89.73\%\pm 1.48\%$, a mean recall of $0.831\pm 0.011$, and a mean precision of $0.921\pm 0.014$. At the image level, the model achieved a mean sensitivity of $0.989\pm 0.022$ on the independent test set, with a mean of $0.2\pm 0.4$ missed positive cases across the five evaluations. These results demonstrate the technical feasibility of a transformer-based artificial intelligence (AI) system as a decision-support aid for fungal region detection in KOH microscopy, pending prospective multi-center validation to establish clinical generalisability. Full article

Background: Atopic dermatitis (AD) is a chronic, relapsing inflammatory dermatosis that is characterized by pruritus, xerosis, and age-dependent clinical heterogeneity. Accurately diagnosing AD remains challenging due to the absence of specific biomarkers and the broad spectrum of conditions that may mimic its presentation. A wide range of inflammatory, infectious, and genetic disorders resemble AD, including seborrheic dermatitis, psoriasis, contact dermatitis, scabies, dermatophytosis, and nummular eczema, as well as rare immunodeficiency and metabolic conditions. This review summarizes the evolution of the clinical features of pediatric AD across infancy, childhood, and adolescence, with a focus on key differential diagnoses. Recognizing age-specific patterns and potential mimickers is essential for improving diagnostic accuracy and guiding appropriate management in pediatric AD. Methods: This study was designed as a narrative review. A structured literature search was conducted of PubMed/MEDLINE for studies published between January 2001 and March 2026 using predefined keywords related to AD, childhood, diagnosis, and differential. Clinical trials, randomized controlled trials, systematic reviews, meta-analyses, and guidelines or consensus documents were included. Studies focusing exclusively on adults or lacking clinical relevance were excluded. A qualitative synthesis was performed due to the heterogeneity in study designs and outcomes. Results: This review demonstrates that pediatric atopic dermatitis exhibits marked age-dependent clinical heterogeneity, with distinct morphological features and lesion distribution patterns across infancy, childhood, and adolescence. Furthermore, the substantial clinical overlap with a broad spectrum of inflammatory, infectious, and genetic disorders—combined with the absence of specific diagnostic biomarkers—significantly complicates accurate differential diagnosis and increases the risk of misclassification. Conclusions: The recognition of age-specific patterns and potential mimickers is essential for improving diagnostic accuracy and guiding appropriate management in pediatric AD. Full article

Background: Superficial fungal infections caused by dermatophyte and non-dermatophyte species are increasing globally. While several comorbid diseases and risk factors have been associated with fungal infections at the individual level, their epidemiological relationships at the population level remains poorly characterized. Objective: We aimed to examine population-level associations between the burden of superficial fungal infections and selected comorbid conditions and risk factors, stratified by age, sex and country. Methods: We obtained years lived with disability (YLDs) for superficial fungal infections, diabetes, psoriasis, and atopic dermatitis and summary exposure values (SEVs) for high body mass index (BMI) and high alcohol intake from Global Burden of Disease Study 2023. Data were obtained for Australia, Brazil, the United Kingdom and the United States for males and females younger than 20 years, 20 to 54 years and 55+ years old. Pearson correlation coefficients were calculated between fungal infection YLDs and each comorbid condition (YLDs) and risk factor (SEVs). Results: Significant positive correlations were observed between superficial fungal infection burden and diabetes (R = 0.6–0.98), high BMI (R = 0.75–0.95), psoriasis (R = 0.59–0.96), and atopic dermatitis (R = 0.51–0.93) in older adults (55 years+). Correlations with high alcohol consumption were more variable across regions and sex. In young–middle-aged adults (20–54 years), moderate-to-strong correlations (R ~ 0.8–0.9) were observed, although patterns were less consistent across countries. In individuals < 20 years, associations were generally weaker, with some positive correlations observed for atopic dermatitis (R = 0.4–0.7) in select countries. Conclusions: The findings demonstrate population-level associations between superficial fungal infections and metabolic, inflammatory, and behavioural risk factors, with stronger correlations observed in older age groups. These patterns may reflect shared demographic, epidemiologic, and clinical patterns across conditions. Full article

Trichophyton indotineae is an emerging dermatophyte associated with extensive, chronic, recalcitrant, and frequently terbinafine-resistant dermatophytosis worldwide. In this study, 30 T. indotineae strains isolated in Italy were investigated. The isolates were obtained from patients originating from Asian countries, from patients from other countries, and from Italian patients who reported no travel outside Italy in the preceding years. Clinical isolates were identified by internal transcribed spacer (ITS) sequencing and analyzed to assess the occurrence and molecular basis of terbinafine resistance. Terbinafine resistance was detected in 18 strains (60%) using a real-time PCR assay. Sequencing of the squalene epoxidase (SQLE) gene revealed mutations associated with resistance, including L393S in nine strains and F397L in another nine strains. NGS analysis confirmed two terbinafine-resistant strains carrying the L393S and F397L mutations, respectively, and detected the A448T mutation in one terbinafine-susceptible strain. These findings demonstrate the presence of terbinafine-resistant T. indotineae across five regions of Italy and confirm the occurrence of SQLE mutations previously linked to antifungal resistance. Data obtained also support a link with endemic Asian areas, other than suggesting the possible occurrence of autochthonous transmission in Italy. Full article

Tinea incognito is an atypical form of dermatophytosis caused by previous use of topical or systemic immunosuppressive therapy, most often corticosteroids. Modification of the clinical presentation frequently leads to diagnostic delay and misdiagnosis, especially in patients with concomitant chronic inflammatory skin diseases such as psoriasis. We present a narrative review of the literature on tinea incognito in patients with psoriasis during immunosuppressive therapy. We screened 386 abstracts and included 16 comparable case reports focusing on tinea incognito occurring in patients with psoriasis or during antipsoriatic treatment. The review summarizes clinical presentations, diagnostic challenges, and therapeutic approaches reported in the literature. Additionally, we present a clinical case of a 27-year-old man with a long history of plaque psoriasis treated with methotrexate and cyclosporine. The patient developed rapidly progressive skin lesions with pustular features and further deterioration despite systemic antipsoriatic therapy. Initial mycological examinations were negative. Histopathological examination revealed a chronic purulent perifollicular inflammatory process with extension into the subcutaneous tissue. The correct diagnosis was confirmed after a repeat skin biopsy with periodic acid–Schiff and Grocott staining and fungal culture of the skin tissue, which revealed Trichophyton rubrum. The review highlights that clinical features are often nonspecific and may overlap with inflammatory dermatoses. This underscores the need for a high index of clinical suspicion for fungal infection in atypical or refractory psoriatic lesions. It also emphasizes the importance of repeated mycological and histopathological examinations to achieve an accurate diagnosis, avoid inappropriate escalation of immunosuppression, and enable timely antifungal treatment. Full article

Dermatophytosis is a superficial fungal skin disease of cats and dogs. The most common pathogens of small animals belong to the genera Microsporum and Trichophyton. It is an important skin disease because it is contagious and can be transmitted to people. Refractory dermatophytosis has become a disease of increasing concern in dermatological practice due to poor responses to standard antifungal therapy. The condition is characterised by chronicity, recurrence, or persistence despite adequate treatment. This report describes the clinical presentation and therapeutic management of refractory dermatophytosis in an 8-year-old intact male Spitz dog weighing 10 kg presenting with persistent alopecia, scaling, erythema, and pruritus despite multiple courses of systemic antifungal agents (itraconazole) and topical antifungal agents (2% miconazole shampoos and terbinafine-containing dusting powder). Diagnosis was confirmed by microscopic examination, culture, and punch biopsy. Due to the lack of response to standard therapy, posaconazole was initiated based on antifungal susceptibility testing (AFST). Marked clinical improvement was observed without adverse effects. This report documents a case of refractory dermatophytosis in which AFST informed the selection of posaconazole therapy. It highlights the diagnostic challenges of recurrent dermatophytosis, suggests that AFST-guided treatment strategies may help manage infections unresponsive to standard antifungal therapy, and demonstrates that posaconazole is a promising alternative antifungal agent for refractory dermatophytosis in dogs. Full article

Healthy and asymptomatic cats may serve as reservoirs of fungal pathogens, facilitating transmission through direct contact or environmental contamination, and they may represent an underrecognized source of subclinical fungal infection in humans, particularly among cat owners and veterinarians. We evaluated the prevalence of fungal species in healthy cats and their owners, assessed potential cat–human transmission, identified feline lifestyle factors associated with Microsporum canis carriage, and evaluated antifungal susceptibility of the most prevalent isolated fungi. We collected 59 cat facial hair and 59 owner nail samples for fungal isolation and identification. Five fungal species were identified, M. canis, Aspergillus flavus, A. niger, A. fumigatus, and A. terreus, which were found in both cats and humans. Aspergillus spp. were the most frequently detected fungi in both groups. Significant associations between cats and owners were observed for M. canis (p = 0.010) and A. niger (p = 0.050). Long-haired cats showed a significantly higher prevalence of carrying M. canis (p = 0.024), while other lifestyle factors were not associated with fungal carriage. The antifungal susceptibility profiles of the tested fungi were broadly similar between feline and human isolates; however, resistance to itraconazole and amphotericin B was detected among Aspergillus spp. Healthy cats and their owners frequently share fungal species, especially M. canis, which suggests possible household zoonotic transmission. Long-haired cats are at higher risk of M. canis carriage. Full article

A commercially available nitric oxide (NO)-releasing solution (NORS) has demonstrated in vitro efficacy for dermatophytosis, but a NO-releasing gel (NORG) may be more suitable for patient self-application. We present a preliminary investigation of NORS for tinea pedis and an in vitro investigation of NORG for dermatophyte infection, to complement the existing published data and expand support for a possible role of NO formulations in superficial dermatophyte infection. In vitro usage of NORS and NORG is reviewed. The antifungal efficacy of NORG was assessed via time-kill assays, zone of inhibition tests with synthetic dermal membrane permeation, and scanning electron microscopy. A randomized, controlled pilot study of NORS for tinea pedis investigated the safety and efficacy of treatment over three consecutive days, with a day-31 follow-up. The NORG demonstrated rapid fungicidal activity against T. rubrum and T. mentagrophytes and effective dermal membrane penetration while retaining antifungal action. Significant morphological damage to fungal cells was noted, indicating possible fungicidal activity. The clinical NORS treatment reduced the clinical symptom severity score by 67% on average, with no significant safety findings. These findings, in addition to existing publications, support NO-releasing formulations as potential therapies that warrant further clinical investigation for superficial fungal infection. Full article

Background/Objectives: This article describes the results of an analysis of the sensitivity of dermatophytosis pathogens to terbinafine, conducted by the authors based on a review of available scientific publications and data from their own research. Currently, no information is available on the sensitivity of Kazakh isolates obtained from patients at dermatological clinics. The aim of this study was to compile data on the resistance of dermatophytes to terbinafine over the past decade worldwide and investigate the sensitivity of dermatophyte isolates collected from patients in Astana, Kazakhstan, to terbinafine. Methods: A systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, utilizing the Pubmed and Cochrane Library databases with specific keywords. The sensitivity of the dermatophytes to terbinafine was assessed using EUCAST E.Def 11.0 method. Results: Screening of terbinafine susceptibility among Kazakh clinical isolates revealed that all Microsporum canis strains (57/57, 100%) were sensitive to the drug. Among 33 Trichophyton spp. isolates, 4 (12.1%) demonstrated resistance to terbinafine, with MIC values ranging from 0.125 to 1.5 µg/mL. The resistant isolates belonged to the species T. indotineae, T. interdigitale, and T. mentagrophytes. Conclusions: Terbinafine remains highly effective against Microsporum canis in Kazakhstan, while a small proportion of Trichophyton isolates show resistance. Continuous monitoring of dermatophyte susceptibility is warranted to guide effective treatment. Full article

Dermatophytosis is a common zoonotic fungal infection in companion animals, most frequently caused by Microsporum canis, while the geophilic species Nannizzia gypsea may occasionally infect cats. Conventional morphological identification of dermatophytes is often challenging due to phenotypic similarities, underscoring the importance of molecular confirmation. In this study, dermatophyte field isolates obtained from cats with suspected dermatophytosis were identified using cultural characteristics and Internal Transcribed Spacer (ITS) region sequencing. Phylogenetic analysis based on ITS sequences showed that the isolates were highly similar to each other and clustered closely with reference strains and previously reported dermatophyte strains from different geographical regions. Subsequently, the in vitro antifungal activity of a propolis extract collected from the Muğla region (Türkiye) was evaluated using the agar dilution method at concentrations ranging from 6.25 to 100 mg/mL. At all tested concentrations, propolis inhibited mycelial growth in all four molecularly confirmed dermatophyte field isolates, whereas substantial growth was observed in the negative control plates. These findings indicate that Muğla propolis exhibits in vitro antifungal activity at the tested concentrations against dermatophyte field isolates and warrants further investigation as a potential natural antifungal source. Full article

We undertook a preliminary clinical study to compare the efficacy of lime essential oil shampoo with a conventional 2% miconazole/chlorhexidine formulation, both in combination with pulse oral itraconazole, in cats with dermatophytosis caused by M. canis. Sixteen affected cats were randomly assigned to receive either lime essential oil shampoo or a 2% miconazole/chlorhexidine formulation. All cats were bathed twice weekly and received itraconazole (5 mg/kg once daily) using a pulse regimen (1 week for every 2 weeks) for 56 days. Clinical assessments, including cytological, direct hair examinations, Wood’s lamp evaluation, total skin lesion score (TLS), and fungal pathogen score (FPS), were performed on days 0, 28, 42, and 56. Hematological and biochemical analyses were conducted on days 0, 28, and 56. By day 56, no significant differences were observed between groups in the cytological, direct hair examination, or Wood’s lamp results. Both groups had significant reductions in TLS and FPS on days 28, 42, and 56 compared to day 0 (p < 0.05). No cutaneous or systemic adverse effects were observed. These findings suggest that lime essential oil shampoo has clinical efficacy comparable to the conventional formulation and may represent a safe natural alternative for the topical management of feline dermatophytosis. Full article

Twenty natural products used in traditional medicine to treat dermatophytosis were evaluated for their efficacy against Trichophyton rubrum, the most frequent dermatophyte infecting humans. For this purpose, aqueous and methanolic extracts were prepared from ash, honey, and plant organs as pure (100%) or diluted (75%, 50%, 25%, 12.5%, 6.25%, 3.125%, and 1.56%) preparations. The extracts were then evaluated by incorporating them into a Sabouraud medium and seeding them with T. rubrum as a fungal culture. The results identify fourteen extracts as being able to completely inhibit T. rubrum growth through either fungistatic or fungicidal activity. The five extracts with the highest efficacy to inhibit T. rubrum growth were further analyzed for their potential to alter in vitro reconstructed human epidermis (RHE). An aqueous extract from Allium sativum produced no tissue alteration in RHE, unlike the extracts from Conyza sumatrensis, Rumex abyssinicus, or Pentas longiflora. The data suggest that preparations used in traditional medicine by rural population in South-Kivu (DR-Congo) might represent valid alternatives to fight dermatophytosis. However, they also illustrate that several preparations remain inefficient and that others may be detrimental to the epidermis. This work reveals that traditional preparations, although affordable and easily available, require an evaluation of their efficacy and safety. Full article

Conventional diagnosis of dermatophytosis relies on fungal culture and microscopic examination, methods that are often time-consuming and lack sensitivity. This study aimed to develop and compare real-time PCR assays for the simultaneous detection and differentiation of three major dermatophytes in dogs: Microsporum canis, Nannizzia gypsea, and Trichophyton mentagrophytes. Three qPCR platforms targeting the chitin synthase 1 (CHS1) gene—SYBR Green, EvaGreen, and dual-emission fluorescence resonance energy transfer (FRET)—were evaluated. The FRET assay demonstrated the highest performance, achieving a detection limit of a single gene copy per reaction and producing distinct melting profiles that enabled accurate species discrimination (M. canis ~56.1 °C, N. gypsea ~53.0 °C, T. mentagrophytes ~51.8 °C). In contrast, SYBR Green and EvaGreen assays showed reduced sensitivity and cross-reactivity with non-target fungi. All assays were validated using three ATCC reference strains, ten clinical isolates of the target dermatophytes, and nine additional fungal species, including Nocardia, Aspergillus, Fusarium, Sporothrix, and Candida. Overall, FRET-qPCR exhibited a 100% specificity and a detection limit of one copy of target gene per reaction, offering a rapid, reliable tool for accurate diagnosis and molecular surveillance of dermatophytosis in companion animals. Full article

Trichophyton indotineae is an emerging dermatophyte species responsible for recalcitrant and terbinafine-resistant dermatophytosis, raising concerns over diagnostic accuracy and treatment efficacy. This study aimed to improve the identification and resistance profiling of T. indotineae by integrating molecular methods with machine learning-assisted analysis of MALDI-TOF mass spectra. A total of 56 clinical isolates within the Trichophyton mentagrophytes complex were analyzed using ITS and ERG1 gene sequencing, antifungal susceptibility testing, and MALDI-TOF MS profiling. Terbinafine resistance was detected in 23 isolates and correlated with specific ERG1 mutations, including F397L, L393S, F415C, and A448T. While conventional MALDI-TOF MS failed to reliably distinguish T. indotineae from closely related species, unsupervised statistical methods (PCA and hierarchical clustering) revealed distinct spectral groupings. Supervised machine learning algorithms, particularly PLS-DA and SVM, achieved 100% balanced accuracy in species classification using 10-fold cross-validation. Biomarker analysis identified discriminatory spectral peaks for both T. indotineae and T. mentagrophytes (3417.29 m/z and 3423.53 m/z). These results demonstrate that combining MALDI-TOF MS with multivariate analysis and machine learning improves diagnostic resolution and may offer a practical alternative to sequencing in resource-limited settings. This approach could enhance the routine detection of terbinafine-resistant T. indotineae and support more targeted antifungal therapy. Full article

Fungal skin infections caused by dermatophytes are of significant veterinary and zoonotic concern. This study investigated the prevalence, risk factors, and treatment outcomes of dermatophytosis in dogs and cats with skin lesions. A total of 140 animals (90 dogs and 50 cats) that presented with skin lesions (alopecia, crusts, pruritus, and scales) were examined. Identification of dermatophyte isolates relied on both phenotypic characteristics and molecular techniques. The molecular approach involved PCR and sequencing of ribosomal DNA regions (ITS1, ITS2, and 5.8S rDNA), complemented by Restriction Fragment Length Polymorphism (RFLP). Treatment regimens included topical clotrimazole, systemic itraconazole, supportive therapy, and a dermatophyte vaccine. Of the 90 dog samples examined, 47 (52.22%) were positive for fungal culture (p = 0.65). In cats, 35 samples (70%) were positive (p < 0.0001). Microsporum canis was the most significant (p < 0.0001) prevalent isolate (60%), followed by Trichophyton mentagrophytes (20%). This study reported the first isolation of T. indotineae in Egypt. Younger animals (<1 year) exhibited a significantly (p < 0.05) higher risk of infection compared with adults (>1 year). Indoor/outdoor housing in cats significantly reduced the risk of infection when compared with indoor housing (p < 0.0001; odds ratio = 0.05). Combination therapy using itraconazole, clotrimazole, supportive treatment, and a dermatophyte vaccine resulted in the fastest clinical recovery (p < 0.0001). These findings underscore the importance of accurate diagnosis and effective treatment strategies for managing dermatophytosis in pets and preventing zoonotic transmission. Full article