Manifestation and associated factors of systemic and local allergy among patients with allergic fungal rhinosinusitis: An observational study.

Allergic fungal rhinosinusitis (AFRS) is a subtype of chronic rhinosinusitis, characterized by excessive immune responses to environmental molds or fungi. The diagnosis and classification of AFRS into systemic and local types remain clinically challenging due to overlapping characteristics. This study investigated the prevalence of AFRS, its manifestation and associated factors in systemic and local AFRS. A total of 200 patients diagnosed with fungal rhinosinusitis underwent both skin provocation tests (SPT) and nasal provocation tests (NPT) to confirm AFRS and classify systemic and local types. Patients were considered to have AFRS if either the SPT or NPT was positive. Among these, patients with systemic AFRS were those who had a SPT positive. Local AFRS was when patients had a negative SPT and a positive NPT. Medical history, serum total IgE level, nasal endoscopy examinations, and CT scans were also recorded. Most patients were female (65.8%), with a mean age of 55.6 years (SD = 14.4). Based on the SPT and NPT results, 31% of patients (n = 62) were diagnosed with AFRS. Among these, 54.8% (n = 34) had systemic AFRS, while 45.2% (n = 28) had local AFRS. Patients with AFRS exhibited significantly higher levels of total IgE, eosinophils, and more pronounced signs and symptoms compared to those without AFRS. However, no statistically significant differences were observed between patients with systemic AFRS and those with local AFRS. AFRS was prevalent in our study. Among patients with AFRS, both systemic AFRS and local AFRS were also prevalent. While allergic indicators and clinical presentations can aid in AFRS diagnosis, minimal distinctions were observed between systemic and local AFRS. A comprehensive assessment incorporating both local and systemic allergic responses through provocation tests, such as a combination of skin and nasal tests, is imperative for optimizing AFRS diagnosis and management.

Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis.

Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.

Aspergillus flavus, mainly causing fungal rhinosinusitis in Sudan, poses health risks due to aflatoxin production. This study revealed diverse levels of aflatoxin and gene expression of clinical isolates by pheno- and genotypic methods, emphasizing the need for vigilant monitoring in the region.

Visual function loss in fungal sphenoid sinusitis: clinical characteristics and outcomes.

Potentially fatal fungal sphenoid sinusitis (FSS) causes visual damage. However, few studies have reported on its visual impairment and prognosis. Five hundred and eleven FSS patients with ocular complications treated at Beijing Tongren Hospital were recruited and clinical features and visual outcomes were determined. Thirty-two of the 511 patients (6%) had visual impairment, with 13 and 19 patients having invasive and noninvasive FSS, respectively. Eighteen patients (56.25%) had diabetes and 2 patient (6.25%) had long-term systemic use of antibiotics (n = 1) and corticosteroids (n = 1). All patients had visual impairment, which was more severe in invasive FSS than in noninvasive FSS. Bony wall defects and sclerosis were observed in 19 patients (59.38%), and 11 patients (34.38%) had microcalcification in their sphenoid sinusitis on computed tomography (CT). After a 5-year follow-up, three patients (9.38%) died. Patients with noninvasive FSS had a higher improvement rate in visual acuity than their counterparts. In the multivariate analysis, sphenoid sinus wall sclerosis on CT was associated with better visual prognosis. FSS can cause vision loss with persistent headaches, particularly in those with diabetes. CT showed the sphenoid sinus wall sclerosis, indicating a better visual prognosis in FSS with visual impairment.

Chronic Rhinosinusitis-Microbiological Etiology, Potential Genetic Markers, and Diagnosis.

Chronic rhinosinusitis (CRS) is a significant public health problem. Bacterial colonization and impaired mucociliary clearance play a significant role in the inflammatory process. Several inflammatory pathways and host defense elements are altered in CRS, which may contribute to observed differences in the microbiome. To date, researching CRS has been difficult due to limited access to the studied tissue and a lack of available biomarkers. Ongoing scientific research is increasingly based on simple and objective analytical methods, including sensors, detection with PCR, and sequencing. Future research on microbiota and human factors should also include genomics, transcriptomics, and metabolomics approaches. This report analyzes the changes that occur in the paranasal sinuses of people with acute and chronic rhinosinusitis, the composition of the microbiota, the human genetic markers that may shed light on the predisposition to CRS, and the advantages and disadvantages of classical and molecular diagnostic methods, as well as addressing the difficulties of sinusitis treatment.

Is maxillary sinusitis and radiographic maxillary sinus opacification associated with an altered microbiology of MRONJ?

OBJECTIVE: Maxillary sinusitis can be a sequela of medication-related osteonecrosis of the jaw (MRONJ). This study aims to characterize the microbiome of maxillary MRONJ with concurrent maxillary sinusitis and radiographic maxillary sinus opacification to determine if there is a relationship between the microbiome of MRONJ and sinus disease. STUDY DESIGN: This retrospective case series was conducted using electronic health records from the University of Pennsylvania and affiliated hospitals. The target population was surgically managed maxillary MRONJ patients. The primary predictor variables were tissue culture results. The primary outcomes were maxillary sinusitis or maxillary sinus opacification. Statistical analysis was performed using chi-squared tests at the 95% confidence interval. RESULTS: Thirty-nine subjects were selected: 25 had sinus opacification and 11 had sinusitis. Resident bacteria were present in 90% of subjects, nonresident bacteria in 74%, and opportunistic organisms in 15%. There were significantly more subjects with chronic sinusitis microbes (79%) than without. There were significantly more gram-positive anaerobes, specifically Propionibacterium, as well as the gram-negative facultative anaerobe, Capnocytophaga, in subjects with concurrent sinusitis. CONCLUSIONS: Maxillary MRONJ with concurrent maxillary sinusitis may be associated with gram-positive anaerobic species, Propionibacterium, and Capnocytophaga colonization. Maxillary MRONJ patients may benefit from sinus evaluation and concurrent surgical intervention.

Reduced Proliferative Capacity and Defense against Staphylococcus aureus in Human Nasal Mucosal Epithelium Lacking ZNF365.

INTRODUCTION: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common chronic inflammatory disease of the nose characterized by barrier disruption and environmental susceptibility, and the deletion of ZNF365 may be a factor inducing these manifestations. However, there is no study on the mechanism of action between CRSwNP and ZNF365. Therefore, this study focuses on the effect of the zinc finger protein ZNF365 on the proliferation of nasal mucosal epithelial cells and their defense against Staphylococcus aureus (S. aureus). METHODS: Immunohistochemistry and Western blot were applied to verify the changes of ZNF365 expression in nasal polyp tissues and control tissues, as well as in primary epithelial cells. ZNF365 was knocked down in human nasal mucosa epithelial cell line (HNEpc), and the proliferation, migration, and transdifferentiation of epithelium were observed by immunofluorescence, QPCR, CCK8, and cell scratch assay. The changes of mesenchymal markers and TLR4-MAPK-NF-κB pathway were also observed after the addition of S. aureus. RESULTS: ZNF365 expression was reduced in NP tissues and primary nasal mucosal epithelial cells compared to controls. Knockdown of ZNF365 in HNEpc resulted in decreased proliferation and migration ability of epithelial cells and abnormal epithelial differentiation (decreased expression of tight junction proteins). S. aureus stimulation further inhibited epithelial cell proliferation and migration, while elevated markers of epithelial-mesenchymal transition and inflammatory responses occurred. CONCLUSION: ZNF365 is instrumental in maintaining the proliferative capacity of nasal mucosal epithelial cells and defending against the invasion of S. aureus. The findings suggest that ZNF365 may participate in the development of CRSwNP.

Microbiome analyses in chronic rhinosinusitis.

In this edition of Rhinology we feature the work of Connell and colleagues from Australia on chronic rhinosinusitis that describes an interesting new pipeline to characterize the bacterial composition of microbiota. We are constantly exposed to a multitude of micro-organisms in the environment and our immune system has the important task discerning and fighting off potential threats. In most people the immune system is doing its job properly and prevents anything untoward from happening. On occasion, a microbe slips by the first (innate) level of defense and we might suffer from an infection. This then activates the second layer of (the adaptive) defense tasked to clear this infection. Sometimes the immune system gets its wrong and starts a full-out defense against something harmless, and an allergy is born. The task of the immune system of doing what is right is even more difficult than it might seem at first sight. In addition to these incidental potential threats, our mucosal surfaces are lined with commensal bacteria which contributes to the complexity of our environment. This collection of bacteria or microbiome has become a major focus of research, as the composition of this microbiome seems related to the health state of the individual. Originally the relationship between the gut microbiome and the development of asthma and allergy was the main focus. In recent years, the focus has been broadened to include the microbiome of the upper and lower airways. In addition to allergy, our field has also been given more and more attention to studying the microbiome in chronic rhinosinusitis.

Reduced Glycolysis and Cytotoxicity in Staphylococcus aureus Isolates from Chronic Rhinosinusitis as Strategies for Host Adaptation.

Chronic rhinosinusitis (CRS) is a multifactorial infection of the nasal cavity and sinuses. In this study, nasal swabs from control donors (N = 128) and patients with CRS (N = 246) were analysed. Culture methods and metagenomics revealed no obvious differences in the composition of the bacterial communities between the two groups. However, at the functional level, several metabolic pathways were significantly enriched in the CRS group compared to the control group. Pathways such as carbohydrate transport metabolism, ATP synthesis, cofactors and vitamins, photosynthesis and transcription were highly enriched in CRS. In contrast, pathways related to lipid metabolism were more representative in the control microbiome. As S. aureus is one of the main species found in the nasal cavity, staphylococcal isolates from control and CRS samples were analysed by microarray and functional assays. Although no significant genetic differences were detected by microarray, S. aureus from CRS induced less cytotoxicity to lung cells and lower rates of glycolysis in host cells than control isolates. These results suggest the differential modulation of staphylococcal virulence by the environment created by other microorganisms and their interactions with host cells in control and CRS samples. These changes were reflected in the differential expression of cytokines and in the expression of Agr, the most important quorum-sensing regulator of virulence in S. aureus. In addition, the CRS isolates remained stable in their cytotoxicity, whereas the cytotoxic activity of S. aureus isolated from control subjects decreased over time during in vitro passage. These results suggest that host factors influence the virulence of S. aureus and promote its adaptation to the nasal environment during CRS.

Gut microbiota and chronic rhinosinusitis: a two-sample Mendelian randomization study.

BACKGROUND: The nasal cavity and gut are interconnected, both housing a rich natural microbiome. Gut microbiota may interact with nasal microbiota and contribute to the development of chronic rhinosinusitis (CRS). However, the specific role of gut microbiota in CRS has not been fully investigated. Therefore, we conducted a two-sample Mendelian randomization study to reveal the potential genetic causal effect of gut microbiota on CRS. METHODS: We performed a two-sample Mendelian Randomization (MR) analysis using aggregated data from genome-wide association studies (GWAS) on gut microbiota and CRS. The primary method used to assess the causal relationship between gut microbiota and CRS was the inverse variance weighting (IVW) method. In addition, sensitivity analyses were conducted to evaluate the robustness of the MR results, including heterogeneity, pleiotropy, and leave-one-out tests. RESULTS: Genetically predicted twelve gut microbiota, including class Coriobacteriia, class Methanobacteria, family Coriobacteriaceae, family Methanobacteriaceae, family Pasteurellaceae, genus Haemophilus, genus Ruminococcus torques group, genus Subdoligranulum, order Coriobacteriales, order Methanobacteriales, order Pasteurellales, and phylum Proteobacteria, demonstrated a potential inhibitory effect on CRS risk (P < 0.05). In addition, four gut microbiota, including family Streptococcaceae, genus Clostridium innocuum group, genus Oscillospira, and genus Ruminococcaceae NK4A214 group, exhibited a causal role in increasing CRS risk (P < 0.05). Sensitivity analyses showed no evidence of heterogeneity or pleiotropy (P > 0.05). CONCLUSIONS: This study reveals the causal relationship between specific gut microbiota and CRS, which provides a new direction and theoretical foundation for the future development of interventions and prevention and treatment strategies for CRS.

[Advances in next-generation sequencing technology to analyze the microbiome of patients with chronic sinusitis].

Chronic rhinosinusitis （CRS） is a chronic inflammatory disease of the sinus mucosa, and the pathogenesis of CRS has not been fully elucidated, and the impact of dysbiosis of the microbiome in the nasal cavity and even in the gut on the pathogenesis of CRS remains controversial. Next-generation sequencing technology, a culture-independent high-throughput sequencing method, contributes to a comprehensive understanding of the CRS microbiome. This article reviews the progress of research on the relevance of bacteria and other microorganisms to CRS and the microbial characteristics of the sinus and intestinal tract of patients with CRS, introduces next-generation sequencing technologies for the study of the CRS microbiome, and discusses the therapeutic prospects of CRS and the possibility of probiotic therapy.

Enhanced phylogenetic insights into the microbiome of chronic rhinosinusitis through the novel application of long read 16S rRNA gene amplicon sequencing.

INTRODUCTION: 16S rRNA next generation sequencing (NGS) has been the de facto standard of microbiome profiling. A limitation of this technology is the inability to accurately assign taxonomy to a species order. Long read 16S sequencing platforms, including Oxford Nanopore Technologies (ONT), have the potential to overcome this limitation. The paranasal sinuses are an ideal niche to apply this technology, being a low biomass environment where bacteria are implicated in disease propagation. Characterising the microbiome to a species order may offer new pathophysiological insights. METHODOLOGY: Cohort series comparing ONT and NGS biological conclusions. Swabs obtained endoscopically from the middle meatus of 61 CRSwNP patients underwent DNA extraction, amplification and dual sequencing (Illumina Miseq (NGS) and ONT GridION). Agreement, relative abundance, prevalence, and culture correlations were compared. RESULTS: Mean microbiome agreement between sequencers was 61.4%. Mean abundance correlations were strongest at a familial/genus order and declined at a species order where NGS lacked resolution. The most significant discrepancies applied to Corynebacterium and Cutibacterium, which were estimated in lower abundance by ONT. ONT accurately identified 84.2% of cultured species, which was significantly higher than NGS. CONCLUSIONS: ONT demonstrated superior resolution and culture correlations to NGS, but underestimated core sinonasal taxa. Future application and optimisation of this technology can advance our understanding of the sinonasal microenvironment.

Temperature influences commensal-pathogen dynamics in a nasal epithelial cell co-culture model.

Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinuses, and microbial dysbiosis associated with CRS is thought to be a key driver of host inflammation that contributes to disease progression. Staphylococcus aureus is a common upper respiratory tract (URT) pathobiont associated with higher carriage rates in CRS populations, where S. aureus-secreted toxins can be identified in CRS tissues. Although many genera of bacteria colonize the URT, few account for the majority of sequencing reads. These include S. aureus and several species belonging to the genus Corynebacterium, including Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum, which are observed at high relative abundance in the healthy URT. Studies have examined bacterial interactions between major microbionts of the URT and S. aureus, but few have done so in the context of a healthy versus diseased URT environment. Here, we examine the role of temperature in commensal, pathogen, and epithelial dynamics using an air-liquid interface cell culture model mimicking the nasal epithelial environment. Healthy URT temperatures change from the nares to the nasopharynx and are increased during disease. Temperatures representative of the healthy URT increase persistence and aggregate formation of commensal C. propinquum and C. pseudodiphtheriticum, reduce S. aureus growth, and lower epithelial cytotoxicity compared to higher temperatures correlating with the diseased CRS sinus. Dual-species colonization revealed species-specific interactions between Corynebacterium species and S. aureus dependent on temperature. Our findings suggest URT mucosal temperature plays a significant role in mediating polymicrobial and host-bacterial interactions that may exacerbate microbial dysbiosis in chronic URT diseases.IMPORTANCEChronic rhinosinusitis is a complex inflammatory disease with a significant healthcare burden. Although presence of S. aureus and microbial dysbiosis are considered mediators of inflammation in CRS, no studies have examined the influence of temperature on S. aureus interactions with the nasal epithelium and the dominant genus of the healthy URT, Corynebacterium. Interactions between Corynebacterium species and S. aureus have been documented in several studies, but none to date have examined how environmental changes in the URT may alter their interactions with the epithelium or each other. This study utilizes a polarized epithelial cell culture model at air-liquid interface to study the colonization and spatial dynamics of S. aureus and clinical isolates of Corynebacterium from people with CRS to characterize the role temperature has in single- and dual-species dynamics on the nasal epithelium.

Sinonasal microbiome and inflammatory profiles in fungal ball and chronic rhinosinusitis.

OBJECTIVE: Fungal balls (FB) are the main form of non-invasive fungal rhinosinusitis found in immunocompetent hosts. Bacterial coinfection affects clinical symptoms. We investigated the sinonasal microbiome and inflammatory profiles in FB and chronic rhinosinusitis (CRS) patients. METHODS: Thirty-three participants were prospectively recruited. Nasal swab samples and sinonasal tissues were collected from controls, and FB and CRS patients. DNA extraction and microbiome analysis using V3-V4 region 16S rRNA sequencing were performed. Inflammatory cytokine levels in the sinonasal tissues, blood eosinophil counts, and serum total IgE were measured. RESULTS: No significant differences were observed in species richness or evenness measures. The phylogenetic tree demonstrated that the FB samples were different from the controls. The sinus bacteria composition differed among the groups. At the phylum level, Firmicutes in FB were significantly depleted compared with those in CRS, while Proteobacteria were more enriched in FB than that in controls and CRS. At the genus level, in FB, Staphylococcus and Corynebacterium were significantly decreased compared to those in the controls. The prevalence of Haemophilus was the highest in FB. Blood eosinophil counts and IL-5 and periostin levels in the sinonasal tissue of the FB group were significantly lower than those in the CRS group. CONCLUSIONS: FB patients had different microbiome compositions and fewer type 2 inflammatory profiles than CRS patients did. However, whether these findings cause FB or result from bacterial and/or fungal infection remains unclear. Further studies are needed to reveal how these differences occur and affect the development of FB and clinical symptoms.

Optimization of diagnostic and procedural codes to identify patients with acute invasive fungal sinusitis.

KEY POINTS: Acute invasive fungal sinusitis (IFS) is a rare disease with high mortality There is no designated International Classification of Diseases code for IFS We propose a novel method to identify IFS using optimized codes complemented by medications.

Microvascular Free Flap Outcomes in Maxillectomy Defects from Invasive Fungal Sinusitis.

OBJECTIVES: Microvascular free tissue transfer is routinely used for reconstructing midface defects in patients with malignancy, however, studies regarding reconstructive outcomes in invasive fungal sinusitis (IFS) are lacking. We aim to describe outcomes of free flap reconstruction for IFS defects, determine the optimal time to perform reconstruction, and if anti-fungal medications or other risk factors of an immunocompromised patient population affect reconstructive outcomes. METHODS: Retrospective review of reconstruction for IFS (2010-2022). Age, BMI, hemoglobin A1c, number of surgical debridements, and interval from the last debridement to reconstruction were compared between patients with delayed wound healing versus those without. Predictor variables for delayed wound healing and the effect of time on free flap reconstruction were analyzed. RESULTS: Twenty-seven patients underwent free flap reconstruction for IFS. Three patients were immunocompromised from leukemia and 21 had diabetes mellitus (DM). Patients underwent an average of four surgical debridements for treatment of IFS. The interval from the last IFS debridement to flap reconstruction was 5.58 months (±5.5). Seven flaps (25.9%) had delayed wound healing. A shorter interval of less than 2 months between the last debridement for IFS and reconstructive free flap procedure was associated with delayed wound healing (Fisher Exact Test p = 0.0062). Other factors including DM, BMI, HgA1c, and bone reconstruction were not associated with delayed wound healing. CONCLUSION: Patients with maxillectomy defects from IFS can undergo microvascular-free flap reconstruction with good outcomes while on anti-fungal medication. Early reconstruction in the first 2 months after the last IFS debridement is associated with delayed wound healing. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1642-1647, 2024.

Acute invasive fungal rhinosinusitis in post-COVID-19 patients in Vietnam.

BACKGROUND: Acute invasive fungal rhinosinusitis (AIFR) is a potentially lethal infection commonly found in immunocompromised patients. It is considered the most aggressive subtype of fungal sinusitis and can lead to severe morbidity and mortality. There was a significant increase in the incidence of AIFR in post-COVID-19 patients compared to AIFR cases before the COVID-19 pandemic. This study aimed to describe the clinical presentation of AIFR associated with COVID-19 illness. METHODS: A retrospective study included 22 patients diagnosed with AIFR with a recent COVID-19 infection. RESULTS: The most frequent disease associated with AIFR was diabetes mellitus (95.5%). The mycological analysis identified infection caused by Aspergillus species in 72.7% of patients. Along with stabilizing hemodynamic parameters and controlling any comorbidities, all patients in the present study underwent combined surgical debridement followed by antifungal medications. The overall survival rate was 72.7%. The chance of developing a fatal outcome was significantly higher if meningitis presented initially (odds ratio 35.63, p < 0.05). CONCLUSION: The presence of meningitis upon initial diagnosis is related to a significantly higher chance of developing a fatal outcome and should be considered, especially in AIFR patients previously treated for COVID-19 infections. Early diagnosis, early use of antifungal agents, aggressive surgical debridement, and control of comorbid conditions remain crucial in managing AIFR.

Factors Impacting Follow-Up Care in Allergic Fungal Rhinosinusitis.

OBJECTIVE: The purpose of this study was to analyze barriers to medical care and follow-up in patients with allergic fungal rhinosinusitis (AFRS). STUDY DESIGN: Cross-sectional questionnaire-based study with retrospective chart review. SETTING: Tertiary Medical Center. METHODS: Subjects with AFRS and chronic rhinosinusitis with nasal polyps (CRSwNP) were prospectively recruited for completion of the Barriers to Care Questionnaire (BCQ) and formal chart review. RESULTS: Fifty-nine AFRS and 51 CRSwNP patients participated. AFRS patients were more likely to be lost to follow-up within 6 months of surgery (35.6% vs 17.7%, P = 0.04) and no-show at least 1 appointment (20.3% vs 5.9%, P = 0.03) compared to CRSwNP patients. Men with AFRS were more likely to have only a single follow-up visit (37.0% vs 3.1%, P < 0.001) and be lost to follow-up (66.7% vs 9.4%, P < 0.001) than women. There were no significant differences in the BCQ between groups; however, rate of questionnaire completion was lower in the AFRS group than the CRS group (62.7% vs 80.4%, P = 0.042). AFRS patients who did not complete the BCQ were more likely to be male (63.6% vs 35.1%, P = 0.034), lost to follow-up (77.3% vs 10.8%, P < 0.0001), and have a single follow-up visit (40.9% vs 5.4%, P < 0.0001). Younger age was associated with increased likelihood of having a single follow-up visit (odds ratio 1.143, 95% CI 1.022-1.276). CONCLUSION: Young, male AFRS patients are more frequently lost to follow-up after surgery and less likely to complete questionnaires assessing barriers to care. Further investigation is needed to assess barriers to follow-up in these at-risk groups.

The vanishing nasal septum sign: a case of severe fungal sinusitis.

Acute invasive fungal sinusitis (AIFS) is a fungal infection of the nasal cavity and paranasal sinuses with associated invasion of adjacent vessels and soft/hard tissues. It usually occurs in immunocompromised patients and may follow a rapid course of less than four weeks with high mortality rate. We report a 39-year-old male with relapse of acute myelogenous leukemia (AML) who was under evaluation for neutropenic fever. On his sinus CT, there was loss of calcification of his nasal septum when compared to a prior head CT, a sign indicative of an aggressive infectious process. He was diagnosed with AIFS and underwent emergent surgical debridement and systemic antifungal therapy, leading to a positive outcome. The sign described on CT ("Vanishing Nasal Septum" sign) may provide an additional, reliable tool to prospectively identify locally aggressive cases of invasive fungal infections of the nasal cavity at an earlier stage and improve patient outcomes.

The destruction of mucosal barriers, epithelial remodeling, and impaired mucociliary clearance: possible pathogenic mechanisms of Pseudomonas aeruginosa and Staphylococcus aureus in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a pathological condition characterized by persistent inflammation in the upper respiratory tract and paranasal sinuses. The epithelium serves as the first line of defense against potential threats and protects the nasal mucosa. The fundamental mechanical barrier is formed by the cell-cell contact and mucociliary clearance (MCC) systems. The physical-mechanical barrier is comprised of many cellular structures, including adhesion junctions and tight junctions (TJs). To this end, different factors, such as the dysfunction of MCC, destruction of epithelial barriers, and tissue remodeling, are related to the onset and development of CRS. Recently published studies reported the critical role of different microorganisms, such as Staphylococcus aureus and Pseudomonas aeruginosa, in the induction of the mentioned factors. Bacteria could result in diminished ciliary stimulation capacity, and enhance the chance of CRS by reducing basal ciliary beat frequency. Additionally, bacterial exoproteins have been demonstrated to disrupt the epithelial barrier and induce downregulation of transmembrane proteins such as occludin, claudin, and tricellulin. Moreover, bacteria exert an influence on TJ proteins, leading to an increase in the permeability of polarized epithelial cells. Noteworthy, it is evident that the activation of TLR2 by staphylococcal enterotoxin can potentially undermine the structural integrity of TJs and the epithelial barrier through the induction of pro-inflammatory cytokines. The purpose of this article is an attempt to investigate the possible role of the most important microorganisms associated with CRS and their pathogenic mechanisms against mucosal surfaces and epithelial barriers in the paranasal sinuses. Video Abstract.

Chrysosporium: A rare cause of allergic fungal rhinosinusitis.

Allergic fungal rhinosinusitis (AFRS) forms a significant group of patients presenting with the commonest health problem encountered in rhinology. Patients commonly present with typical symptoms of sinusitis, and the diagnosis is often made after imaging and/or intraoperatively. Infections caused by Chrysosporium species are very rare and are very rarely been reported to cause sinusitis in humans. Usually, human chrysosporial infections are mild and unmarked by symptoms. We report a rare case of allergic fungal sinusitis (AFS) caused by Chrysosporium species in a 41-year-old male with the history of diabetes mellitus.