Decoding the role of DNA methylation in allergic diseases: from pathogenesis to therapy.

Allergic diseases, characterized by a broad spectrum of clinical manifestations and symptoms, encompass a significant category of IgE-mediated atopic disorders, including asthma, allergic rhinitis, atopic dermatitis, and food allergies. These complex conditions arise from the intricate interplay between genetic and environmental factors and are known to contribute to socioeconomic burdens globally. Recent advancements in the study of allergic diseases have illuminated the crucial role of DNA methylation (DNAm) in their pathogenesis. This review explores the factors influencing DNAm in allergic diseases and delves into their mechanisms, offering valuable perspectives for clinicians. Understanding these epigenetic modifications aims to lay the groundwork for improved early prevention strategies. Moreover, our analysis of DNAm mechanisms in these conditions seeks to enhance diagnostic and therapeutic approaches, paving the way for more effective management of allergic diseases in the future.

[Expert consensus on the diagnosis and treatment of respiratory diseases exacerbated by nonsteroidal anti-inflammatory drugs （2024, Chengdu）].

Non-steroidal anti-inflammatory drugs-exacerbated respiratory disease （N-ERD） is a chronic respiratory disease characterized by eosinophilic inflammation, featuring chronic rhinosinusitis （CRS）, asthma, and intolerance to cyclooxygenase 1 （COX-1） inhibitors. The use of these medications can lead to an acute worsening of rhinitis and asthma symptoms. This condition has not yet received sufficient attention in China, with a high rate of misdiagnosis and a lack of related research. The Chinese Rhinology Research Group convened a group of leading young experts in otolaryngology from across the country, based on the latest domestic and international evidence-based medical practices to formulate this consensus.The consensus covers the epidemiology, pathogenesis, clinical manifestations, diagnostic methods, and treatment strategies for N-ERD, including pharmacotherapy, surgery, biologic treatments, and desensitization therapy. The goal is to improve recognition of N-ERD, reduce misdiagnosis, and enhance treatment outcomes.

Role of TRPV1 and TRPA1 in TSLP production in nasal epithelial cells.

BACKGROUND: TRP protein is sensitive to external temperature changes, but its pathogenic mechanism in the upper airway mucosa is still unclear. OBJECTIVE: To investigate the mechanism of TRPV1and TRPA1 in regulating the secretion of inflammatory factors in nasal epithelial cells. METHODS: The expression of TRPV1 and TRPA1 in nasal mucosal epithelial cells was investigated using immunofluorescence assays. Epithelial cells were stimulated with TRPV1 and TRPA1 agonists and antagonists, and changes in Ca2+ release and inflammatory factor secretion in epithelial cells were detected. TSLP secretion stimulated with the calcium chelating agent EGTA was evaluated. The transcription factor NFAT was observed by immunofluorescence staining. RESULTS: TRPV1 and TRPA1 expression was detected in nasal epithelial cells, and Ca2+ influx was increased after stimulation with agonists. After the activation of TRPV1 and TRPA1, the gene expression of TSLP, IL-25, and IL-33 and the protein expression levels of TSLP and IL-33 were increased, and only TSLP could be inhibited by antagonists and siRNAs. After administration of EGTA, the secretion of TSLP was inhibited significantly, and the expression of the transcription factor NFAT in the nucleus was observed after activation of the TRPV1 and TRPA1 proteins in epithelial cells. CONCLUSION: Activation of TRPV1 and TRPA1 on nasal epithelial cells stimulates the generation of TSLP through the Ca2+/NFAT pathway. It also induces upregulation of IL-25 and IL-33 gene expression levels and increased levels of IL-33 protein, leading to the development of airway inflammation.

Efficacy and safety of stapokibart (CM310) in uncontrolled seasonal allergic rhinitis (MERAK): an investigator-initiated, placebo-controlled, randomised, double-blind, phase 2 trial.

Background: There is no trial to assess the benefits of periodically using biologics during the pollen season in patients with uncontrolled seasonal allergic rhinitis (SAR), who have moderate-to-severe symptoms even after standard-of-care. This trial aimed to evaluate the efficacy and safety of the add-on administration of stapokibart, a humanised monoclonal antibody that targets interleukin-4 receptor alpha, in patients with uncontrolled SAR. Methods: In this investigator-initiated, randomised, double-blind, placebo-controlled trial, eligible patients received either stapokibart 600-300 mg weekly (QW), every 2 weeks (Q2W), or placebo QW for 4 weeks. All patients were given mometasone furoate nasal spray and loratadine throughout the trial. The primary endpoint was the mean change from baseline in daily reflective total nasal symptom score (rTNSS) during 2-week treatment. Secondary efficacy outcomes included: the mean change from baseline in daily rTNSS during 4-week treatment; the mean changes and the mean percentage changes from baseline during 2-week and 4-week treatment in 1) daily rTNSS and reflective total ocular symptom score (rTOSS), 2) morning (AM)/evening (PM) rTNSS and rTOSS, 3) AM instantaneous total nasal symptom score (iTNSS) and instantaneous total ocular symptom score (iTOSS), 4) individual nasal and ocular symptoms; the change from baseline in Rhinoconjunctivitis Quality of-Life Questionnaire score during 4-week treatment. Exploratory endpoints included the change of prespecified markers related to type 2 inflammation pre- and post-treatment. Safety, immunogenicity, and pharmacokinetics were also evaluated. This study is registered with www.clinicaltrials.gov (NCT05470647). Findings: Between August 17, 2022, and December 28, 2022, 92 patients with uncontrolled SAR were enrolled from 4 centres in China and randomly assigned to receive stapokibart 600-300 mg QW (n = 31), stapokibart 600-300 mg Q2W (n = 30), or placebo QW (n = 31), of whom 86 (93%) completed the study. Both stapokibart Q2W and QW did not significantly improve mean change from baseline in daily rTNSS compared with placebo in 2 weeks. The least-squares (LS) mean differences (97.5% confidence interval [CI]) compared with placebo were -1.0 (-2.3, 0.2) in stapokibart Q2W group (p = 0.065) and -0.2 (-1.5, 1.0) in stapokibart QW group (p = 0.67). For the secondary outcomes, compared with placebo, stapokibart Q2W presented significant improvements in the mean percentage change from baseline in daily rTNSS in 2 weeks (LS mean difference -12.9%, 95% CI -25.3%, -0.4%, p = 0.043), as well as AM iTNSS over 2 weeks (LS mean difference -17.4%, 95% CI -31.0%, -3.8%, p = 0.013) and 4 weeks (LS mean difference -15.4%, 95% CI -29.0%, -1.9%, p = 0.026). Additionally, the nasal congestion score was significantly lower in stapokibart Q2W than placebo during 2-week (LS mean difference -0.4, 95% CI -0.7, -0.1, p = 0.014) and 4-week (LS mean difference -0.4, 95% CI -0.7, -0.04, p = 0.028) treatment. Treatment-emergent adverse events (TEAEs) occurred in 48% (15/31), 33% (10/30), and 61% (19/31) of patients receiving stapokibart QW, Q2W, and placebo, respectively. Most reported TEAEs were sinus bradycardia, hyperlipidaemia, and blood uric acid increased. Interpretation: In this phase 2 trial, both stapokibart regimens had an acceptable safety and tolerability profile but did not significantly improve daily rTNSS in patients with uncontrolled SAR. The efficacy of stapokibart in patients with uncontrolled SAR is being further investigated in ongoing phase 3 trials (clinicaltrials.gov, NCT05908032). Funding: Ministry of Science and Technology of the People's Republic of China; Ministry of Education of the People's Republic of China; National Natural Science Foundation of China; Chinese Academy of Medical Sciences.

Pericyte loss leads to microvessel remodeling and nasal polyp formation.

BACKGROUND: Chronic rhinosinusitis (CRS) may be caused by increased vascular permeability and inflammatory cell leakage in the subepithelial tissue. AIMS/OBJECTIVES: The aim of this study is to clarify the role of pericytes in tissue edema, microvessel dysfunction and vascular remodeling mechanisms in patients of CRS with nasal polyps (CRSwNP). MATERIAL AND METHODS: A total of 63 tissue samples were collected, including 42 CRSwNP samples (22 eosinophilic CRSwNP (eCRSwNP) and 20 non-eosinophilic CRSwNP (non-eCRSwNP) samples) and 21 samples of CRS without nasal polyps (CRSsNP). The samples were stained by immunofluorescence to measure microvessel density (MVD) and microvessel pericyte coverage index (MPI). RESULTS: We found that the albumin expression in the eCRSwNP group was significantly increased (p < .05). The MPI was significantly decreased (p <.05). There was a significant negative correlation between the MPI and the plasma albumin level (r=-0.82, p < .05). The MPI was negatively correlated with eosinophilic count (r=-0.77, p < .05). In the eCRSwNP group, the expressions of IL-4, Ang-1 and Ang-2 were increased compared with those in the control group. CONCLUSIONS AND SIGNIFICANCE: Pericyte loss may induce microvessel dysfunction, affect the development of interstitial edema and eosinophilic exosmosis in eCRSwNP, and contribute to the formation and maintenance of nasal polyps.

Cancer stem cells of head and neck squamous cell carcinoma; distance towards clinical application; a systematic review of literature.

Head and neck squamous cell carcinoma (HNSCC) is the major pathological type of head and neck cancer (HNC). The disease ranks sixth among the most common malignancies worldwide, with an increasing incidence rate yearly. Despite the development of therapy, the prognosis of HNSCC remains unsatisfactory, which may be attributed to the resistance to traditional radio-chemotherapy, relapse, and metastasis. To improve the diagnosis and treatment, the targeted therapy for HNSCC may be successful as that for some other tumors. Nanocarriers are the most effective system to deliver the anti-cancerous agent at the site of interest using passive or active targeting approaches. The system enhances the drug concentration in HCN target cells, increases retention, and reduces toxicity to normal cells. Among the different techniques in nanotechnology, quantum dots (QDs) possess multiple fluorescent colors emissions under single-source excitation and size-tunable light emission. Dendrimers are the most attractive nanocarriers, which possess the desired properties of drug retention, release, unaffecting by the immune system, blood circulation time enhancing, and cells or organs specific targeting properties. In this review, we have discussed the up-to-date knowledge of the Cancer Stem Cells of Head and Neck Squamous Cell Carcinoma. Although a lot of data is available, still much more efforts remain to be made to improve the treatment of HNSCC.

A Decade of Pathogenesis Advances in Non-Type 2 Inflammatory Endotypes in Chronic Rhinosinusitis: 2012-2022.

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by localized inflammation of the upper airways. CRS includes two main phenotypes, namely, CRS with nasal polyps and CRS without nasal polyps. The phenotype-based classification method cannot reflect the pathological mechanism. The endotype-based classification method has been paid more and more attention by researchers. It is mainly divided into type 2 and non-type 2 endotypes. The mechanism driving the pathogenesis of non-type 2 inflammation is currently unknown. In this review, the PubMed and Web of Science databases were searched to conduct a critical analysis of representative literature works on the pathogenesis of non-type 2 inflammation in CRS published in the past decade. This review summarizes the latest evidence that may lead to the pathogenesis of non-type 2 inflammation. It is the main method that analyzing the pathogenesis from the perspective of immunology. Genomics and proteomics technique provide new approaches to the study of the pathogenesis. Due to differences in race, environment, geography, and living habits, there are differences in the occurrence of non-type 2 inflammation, which increase the difficulty of understanding the pathogenesis of non-type 2 inflammation in CRS. Studies have confirmed that non-type 2 endotype is more common in Asian patients. The emergence of overlap and unclassified endotypes has promoted the study of heterogeneity in CRS. In addition, as the source of inflammatory cells and the initiation site of the inflammatory response, microvessels and microlymphatic vessels in the nasal mucosal subepithelial tissue participate in the inflammatory response and tissue remodeling. It is uncertain whether CRS patients affect the risk of infection with SARS-CoV-2. In addition, the pathophysiological mechanism of non-type 2 CRS combined with COVID-19 remains to be further studied, and it is worth considering how to select the befitting biologics for CRS patients with non-type 2 inflammation.

Recent advances in understanding the effects of T lymphocytes on mucosal barrier function in allergic rhinitis.

Allergic rhinitis is a non-infectious chronic inflammatory disease of the nasal mucosa that affects T cells and their cytokines. T cells play significant roles in the development of allergic inflammatory diseases by orchestrating mechanisms underlying innate and adaptive immunity. Although many studies on allergic rhinitis have focused on helper T cells, molecular makeup, and pathogenesis-related transduction pathways, pathological mechanisms have not yet been completely explored. Recent studies have suggested that T cell status may play an important role in the interaction between T cells and the nasal mucosal barrier in allergic rhinitis. This study aimed to explore the interactions between T cells and nasal mucosal barriers in allergic rhinitis and to review the therapeutic modalities of pertinent biological agents involving T cells.

[A multi-center observation of the therapeutic efficacy of Bencycloquidium bromide in the treatment of seasonal allergic rhinitis with predominant symptoms of rhinorrhea].

Objective:To observe the efficacy and safety of the M receptor antagonist Bencycloquidium bromide nasal spray in treatment of seasonal allergic rhinitis with runny nose as the main symptom. Methods:From August 2021 to September 2021, 134 patients with seasonal allergic rhinitis were enrolled in the otolaryngology Outpatient Department of Peking University Third Hospital, First Affiliated Hospital of Harbin Medical University and China-Japanese Friendship Hospital of Jilin University, including 71 males and 63 females, with a median age of 38 years. TNSS score and visual analogue scale（VAS） of total nasal symptoms were observed during 2 weeks of treatment with Bencycloquidium bromide nasal spray. Results:TNSS score decreased from （8.89±3.31） on day 0 to （3.71±2.51） on day 14（P<0.001）, VAS score of nasal symptoms decreased from （24.86±7.40） on day 0 to （6.84±5.94） on day 14（P<0.001）, VAS score of rhinorrhoea decreased from （6.88±2.06） on day 0 to （1.91±1.81） on day 14（P<0.001）. Rhinoconjunctivitis quality of life questionnaire（RQLQ） score decreased from （94.63±33.35） on day 0 to （44.95±32.28） on day 14（P<0.001）. The incidence of adverse reaction was low and no serious adverse events occurred during the whole experiment. Conclusion:Bencycloquidium bromide nasal spray has significant efficacy and good safety in the treatment of seasonal allergic rhinitis.

Chinese Expert Consensus on the Use of Biologics in Patients with Chronic Rhinosinusitis (2022, Zhuhai).

BACKGROUND: Chronic rhinosinusitis (CRS) is a common inflammatory disease in otolaryngology, mainly manifested as nasal congestion, nasal discharge, facial pain/pressure, and smell disorder. CRS with nasal polyps (CRSwNP), an important phenotype of CRS, has a high recurrence rate even after receiving corticosteroids and/or functional endoscopic sinus surgery. In recent years, clinicians have focused on the application of biological agents in CRSwNP. However, it has not reached a consensus on the timing and selection of biologics for the treatment of CRS so far. SUMMARY: We reviewed the previous studies of biologics in CRS and summarized the indications, contraindications, efficacy assessment, prognosis, and adverse effects of biologics. Also, we evaluated the treatment response and adverse reactions of dupilumab, omalizumab, and mepolizumab in the management of CRS and made recommendations. KEY MESSAGES: Dupilumab, omalizumab, and mepolizumab have been approved for the treatment of CRSwNP by the US Food and Drug Administration. Type 2 and eosinophilic inflammation, need for systemic steroids or contraindication to systemic steroids, significantly impaired quality of life, anosmia, and comorbid asthma are required for the use of biologics. Based on current evidence, dupilumab has the prominent advantage in improving quality of life and reducing the risk of comorbid asthma in CRSwNP among the approved monoclonal antibodies. Most patients tolerate biological agents well in general with few major or severe adverse effects. Biologics have provided more options for severe uncontrolled CRSwNP patients or patients who refuse to have surgery. In the future, more novel biologics will be assessed in high-quality clinical trials and applied clinically.

Clinical and upper airway characteristics of 3715 patients with the Omicron variant of SARS-Cov-2 in Changchun, China.

OBJECTIVE: The spread of the novel SARS-Cov-2 variant Omicron created a challenging public health situation in a number of countries. In March 2022, Omicron emerged in Changchun, China, and the number of patients infected rapidly increased. The prevalence of Omicron infection symptoms differs from that of Delta, with more upper airway clinical symptoms apparent. This study aimed to investigate the clinical and upper airway characteristics of the Omicron variant. MATERIALS AND METHODS: In this retrospective study, we collected data from participants in Changchun who had tested positive for Omicron with quantitative polymerase chain reaction between 10 March and 30 May 2022 using telephone interviews. The questionnaire was designed by the research team based on the number of upper airway symptoms using the visual analogue scale. We also considered age, sex, vaccination status, general symptoms, and cure period. RESULTS: A total of 3715 patients (2056 males and 1659 females) with mild COVID-19 from the Omicron variant were included. The patients had a mean age of 38.63 ( ± 13.97) years (range 2-86 years). The vaccine uptake rate was 91.33 % (8.66 %, 4.58 %, 65.33 %, and 21.43 % had received zero, one, two, and three doses, respectively). The incidence of upper airway symptoms, including throat and nasal symptoms, was 54.21 %. Throat symptoms were the most common during Omicron infection (49.12 %). Nasal symptoms were also common (20.08 %). The incidence of lower airway symptoms was 25.60 %, and gastrointestinal symptoms was 10.87 %. The incidence of general symptoms was 55.26 %. The cure period ranged from three to 37 days, with a mean of 10.24 ± 4.69 days. We compared the upper airway symptom severity for Omicron among different vaccination statuses and found no differences. CONCLUSIONS: The main clinical characteristics of the SARS-Cov-2 Omicron variant are upper airway symptoms and general symptoms. Fever remains the most common symptom, followed by mild dry cough. There was no association between Omicron infection and COVID-19 vaccines, and the vaccination status might have been ineffective against upper airway symptom severity by Omicron.

[Interpretation of the 2021 American Academy of Allergy, Asthma and Immunology expert consensus on the treatment of postinfectious olfactory dysfunction].

Respiratory tract viruses are the second leading cause of olfactory dysfunction. Between 2019 to 2022, the world has been plagued by the problem of olfaction caused by the COVID-19. As we learn more about the impact of severe acute respiratory syndrome coronavirus 2（SARS-CoV-2）, with the recognition that olfactory dysfunction is a key symptom of this disease process, there is a greater need than ever for evidence-based management of postinfectious olfactory dysfunction（PIOD）. The Clinical Olfactory Working Group has proposed theconsensus on the roles of PIOD. This paper is the detailed interpretation of the consensus.

Short-term postoperative efficacy of steroid-eluting stents for eosinophilic chronic rhinosinusitis with nasal polyps: A randomized clinical trial.

BACKGROUND: Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is a refractory clinical phenotype with a high symptom burden and relapse rate. Steroid-eluting stents are safe and effective for reducing polyp size, symptom burden, and the need for revision sinus surgery. In this study we aimed to evaluate the efficacy and safety of steroid-eluting stent implantation on the surgical outcomes of patients with ECRSwNP. METHODS: This prospective, multicenter, randomized, intrapatient-controlled trial recruited patients 18 to 65 years of age with ECRSwNP who required surgery. Ninety-eight patients were enrolled and randomly implanted with absorbable steroid-eluting stents containing mometasone furoate in one sinus at the end of surgery. All patients received standard postoperative care and follow-up. The primary outcome was the Lund-Kennedy endoscopic score within 12 weeks postsurgery. Secondary outcomes included nasal symptoms scores, nasal resistance, acoustic rhinometry, nasal nitric oxide levels, 3-dimensional volumetric computed tomography scores, and eosinophil counts in the ethmoid mucosa. RESULTS: Ninety-five patients completed the trial. At postoperative weeks 4, 8, and 12, the Lund-Kennedy scores were significantly lower on the treatment side than on the control side (all p < 0.01). Compared with the treatment side, the control side exhibited higher tissue eosinophilia at week 4 and higher volumetric, nasal obstruction, and total nasal symptom scores at postoperative week 8 (p = 0.011, p = 0.011, p < 0.01, and p = 0.001, respectively). No adrenal cortical suppression or serious side effects were observed. CONCLUSION: Steroid-eluting stents reduce postoperative sinus mucosal edema, and eosinophilic inflammation, with persistent effects after stent disintegration, and are a good supplementary postsurgical treatment in patients with ECRSwNP.

Mechanism of Lower Airway Hyperresponsiveness Induced by Allergic Rhinitis.

Allergic rhinitis is a global illness that puzzles many researchers. Most patients with allergic rhinitis also have lower airway hyperresponsiveness, and an allergic rhinitis attack can increase lower airway hyperresponsiveness. However, the mechanism of the effect of allergic rhinitis on the lower airways is still unclear. In this paper, the effects of allergic rhinitis on the lower airways are studied in terms of epidemiology, anatomy, pathophysiology, nasal function loss, inflammation drainage, nasobronchial reflex, and whole-body circulatory flow to determine the mechanism involved and provide ideas for future diagnosis, treatment, and experiments.

The Role of Small Extracellular Vesicles and MicroRNAs in the Diagnosis and Treatment of Allergic Rhinitis and Nasal Polyps.

Allergic rhinitis and nasal polyps are common otorhinolaryngological diseases. Small extracellular vesicles and microRNAs have recently become major research topics of interest due to their key regulatory roles in cancer, inflammation, and various diseases. Although very detailed and in-depth studies on the pathogenesis and pathophysiology of allergic rhinitis and nasal polyps have been conducted, few studies have assessed the regulatory effects of exosomes and microRNAs on allergic rhinitis and nasal polyps. This paper reviews the studies on small extracellular vesicles and microRNAs in allergic rhinitis and nasal polyps conducted in recent years and focuses on the regulation of small extracellular vesicles and microRNAs in allergic rhinitis and nasal polyps with the aim of providing insights for the future diagnosis and treatment of allergic rhinitis and nasal polyps.

Organoid Models for Salivary Gland Biology and Regenerative Medicine.

The salivary gland is composed of an elegant epithelial network that secrets saliva and maintains oral homeostasis. While cell lines and animal models furthered our understanding of salivary gland biology, they cannot replicate key aspects of the human salivary gland tissue, particularly the complex architecture and microenvironmental features that dictate salivary gland function. Organoid cultures provide an alternative system to recapitulate salivary gland tissue in vitro, and salivary gland organoids have been generated from pluripotent stem cells and adult stem/progenitor cells. In this review, we describe salivary gland organoids, the advances and limitations, and the promising potential for regenerative medicine.

Contribution of Regulatory T Cell Methylation Modifications to the Pathogenesis of Allergic Airway Diseases.

Regulatory T (Treg) cells are a subtype of CD4+ T cells that play a significant role in the protection from autoimmunity and the maintenance of immune tolerance via immune regulation. Epigenetic modifications of Treg cells (i.e., cytosine methylation at the promoter region of the transcription factor, Forkhead Box P3) have been found to be closely associated with allergic diseases, including allergic rhinitis, asthma, and food allergies. In this study, we highlighted the recent evidence on the contribution of epigenetic modifications in Treg cells to the pathogenesis of allergic diseases. Moreover, we also discussed directions for future clinical treatment approaches, with a particular emphasis on Treg cell-targeted therapies for allergic disorders.

Ten-eleven translocation 2 modulates allergic inflammation by 5-hydroxymethylcytosine remodeling of immunologic pathways.

Allergic rhinitis (AR) is an allergen-specific immunoglobulin E-mediated inflammatory disease. Both genetic and environmental factors could play a role in the pathophysiology of AR. 5-methylcytosine (5mC) can be converted to 5-hydroxymethylcytosine (5hmC) by the ten-eleven translocation (Tet) family of proteins as part of active deoxyribonucleic acid (DNA) demethylation pathway. 5hmC plays an important role in the regulation of gene expression and differentiation in immune cells. Here, we show that loss of Tet protein 2 (Tet2) could impact the severity of AR in the ovalbumin-induced mouse model. Genome-wide 5hmC profiling of both wild-type and Tet2 KO mice in response to AR revealed that the loss of Tet2 could lead to 5hmC alteration at specific immune response genes. Both partial loss and complete loss of Tet2 alters the 5hmC dynamic remodeling for the adaptive immune pathway as well as cytokines. Thus, our results reveal a new role of Tet2 in immunology, and Tet2 may serve as a promising target in regulating the level of immune response.

Erratum: MicroRNA-26b suppresses autophagy in breast cancer cells by targeting DRAM1 mRNA, and is downregulated by irradiation.

[This corrects the article DOI: 10.3892/ol.2017.7452.].

Chinese expert recommendation on transnasal corticosteroid nebulization for the treatment of chronic rhinosinusitis 2021.

Corticosteroids are efficacious in treating chronic rhinosinusitis (CRS), but concerns on the potential side effects remain, especially for long-term usage of systemic corticosteroids. Accumulated evidence shows that transnasal nebulization may be a reasonable solution in balancing both efficacy and safety. However, no consensus or guideline has been formulated on the use of steroid transnasal nebulization in treating CRS. The consensus is achieved through literature review and exchange of Chinese experts in Group of Otorhinolaryngology and Ophthalmology, Chinese Society of Allergy (CSA). This document covers the development, equipment, pharmacological mechanism, and evidence-based efficacy and safety, as well as the special concern of the application of steroid transnasal nebulization during the coronavirus disease (COVID-19) pandemic. The expert consensus clarifies the application of steroid transnasal nebulization in treating CRS and common comorbidities during the perioperative and postoperative periods.