Search Results (5)

Deep dermatophytosis is a rare, life-threatening fungal infection characterised by the invasion of dermatophytes beyond the superficial layers of keratinised tissue into the dermis and subcutaneous tissues. The present review aimed to identify the current knowledge on the role of Caspase Recruitment Domain-containing protein 9 (CARD9) deficiency in the pathogenesis, clinical spectrum, diagnosis, and management of deep dermatophytosis. For innate immune activation, CARD9 acts as an adaptor molecule. Basically, CARD9 helps mediate the connection between the fungal pattern recognition receptor (Dectin-1) and the NF-κB and MAPK signalling pathways, and it mediates cytokine production, thereby activating phagocytic activities. Thereby, any change or mutation in the CARD9 gene may disrupt these pathways, leading to dysfunctional neutrophils and impaired Th17-mediated antifungal immunity. Clinically, patients with CARD9 deficiency are immunocompetent but susceptible to recurrent and/or severe fungal infections [Candida, dermatophytes (Trichophyton spp.), and phaeohyphomycetes]. Deep dermatophytosis in these patients is usually chronic, treatment-resistant, and characterized by erythematous papules, nodules, plaques, ulcers, or necrotic lesions, most of which occur on the lower limbs. It usually occurs in adulthood and is more common in males. There have been instances of geographic clustering of CARD9 deficiency in Asia, North Africa, and the Middle East. Early recognition and genetic diagnosis of CARD9 mutations in patients with recurrent or atypical deep dermatophytosis. Although antifungal therapy is essential, hematopoietic stem cell transplantation can be a definitive treatment for selected patients with CARD9 deficiency. Thus, CARD9 deficiency is a critical factor in the better management of patients but remains an underrecognized cause of severe, treatment-resistant deep dermatophytosis, and early genetic diagnosis is essential for guiding targeted management and improving patient outcomes. This review emphasises the importance of CARD9 in antifungal immunity and underscores the need for greater clinical awareness and the incorporation of genetic evaluation into the management of deep dermatophytosis. Full article

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

Purpose of review. Inflammatory tinea is an uncommon group of dermatophyte entities that predominantly cause fungal infection of the skin and hair. This review intends to present all of the available evidence regarding its epidemiology, etiopathogenesis, clinical features, and diagnostic methods as well as treatments recommended for various inflammatory tinea infections. This article provides a review of Majocchi’s granuloma and dermatophytic or Hadida’s disease. Recent findings. The new phylogenetic classification of dermatophytes includes nine genera, and those that affect humans are Trichophyton, Microsporum, Epidermophyton, and Nannizzia. Furthermore, molecular advancements have revealed impaired antifungal immune responses caused by inflammatory tinea, which are detailed in this article. Summary. The common denominator in these pathologies is the presence of impaired immune responses and, consequently, an impaired inflammatory response by the host. It is necessary to be familiar with these immunological characteristics in order to use the appropriate diagnostic methods and to provide adequate treatment. Full article

Trichophyton rubrum is causing an increasing number of invasive infections, especially in immunocompromised and diabetic patients. The fungal invasive infectious process is complex and has not yet been fully elucidated. Therefore, this study aimed to understand the cellular and molecular mechanisms during the interaction of macrophages and T. rubrum. For this purpose, we used a co-culture of previously germinated and heat-inactivated T. rubrum conidia placed in contact with human macrophages cell line THP-1 for 24 h. This interaction led to a higher level of release of interleukins IL-6, IL-2, nuclear factor kappa beta (NF-κB) and an increase in reactive oxygen species (ROS) production, demonstrating the cellular defense by macrophages against dead fungal elements. Cell viability assays showed that 70% of macrophages remained viable during co-culture. Human microRNA expression is involved in fungal infection and may modulate the immune response. Thus, the macrophage expression profile of microRNAs during co-culture revealed the modulation of 83 microRNAs, with repression of 33 microRNAs and induction of 50 microRNAs. These data were analyzed using bioinformatics analysis programs and the modulation of the expression of some microRNAs was validated by qRT-PCR. In silico analysis showed that the target genes of these microRNAs are related to the inflammatory response, oxidative stress, apoptosis, drug resistance, and cell proliferation. Full article

Dermatophytes are keratinophilic fungi responsible for benign and common forms of infection worldwide. However, they can lead to rare and severe diseases in immunocompromised patients. Severe forms include extensive and/or invasive dermatophytosis, i.e., deep dermatophytosis and Majocchi’s granuloma. They are reported in immunocompromised hosts with primary (autosomal recessive CARD9 deficiency) or acquired (solid organ transplantation, autoimmune diseases requiring immunosuppressive treatments, HIV infection) immunodeficiencies. The clinical manifestations of the infection are not specific. Lymph node and organ involvement may also occur. Diagnosis requires both mycological and histological findings. There is no consensus on treatment. Systemic antifungal agents such as terbinafine and azoles (itraconazole or posaconazole) are effective. However, long-term outcome and treatment management depend on the site and extent of the infection and the nature of the underlying immunodeficiency. Full article