xRead - Nonallergic Rhinitis (September 2025)

4 2

Clinical Reviews in Allergy & Immunology (2024) 67:40–46

were addressed through discussion, with a designated third author available for arbitration. Data analysis was conducted using a two-pronged approach. Numerical data from images was extracted using OriginPro software and used to supplement missing infor mation from the articles. Review Manager 5.4 was then employed to analyze the extracted data. The primary outcome measure focused on the overall treatment effects of NAR, evaluated by comparing scores or the number of patients showing improvement at the end of the study. All treatment groups were combined regardless of capsaicin application method for this analysis. Subgroup analysis was explored to investigate the effects of different dosages, decongestion medicine, and topical lidocaine use. Due to insufficient similar trials, this analysis was conducted narratively. Additionally, the study examined the potential for advanced diagnostic approaches to suggest alternative superior clinical approaches or more precise treatment recommendations. The process of comprehensive article identification is illus trated in Fig. 1. A total of 141 articles including two stud ies from a previous review were initially identified through searching various databases. Subsequently, 29 duplicate records were removed from the dataset. After considering the quality of the remaining articles, 52 articles that lacked relevance or did not correspond to the intended study type were excluded. Additionally, ten articles were eliminated due to insufficient available results. One more article was deemed ineligible upon assessment, owing to the incom parable nature of the outcomes. Consequently, these nine studies were consolidated and included in the meta-analysis and systematic review. Results Results of the Search

limited available clinical data in this field. Studies reporting unavailable results or deemed irrelevant were excluded. The intervention focus was on capsaicin solutions and medications related to capsaicin, including ICX72, a propri etary homeopathic preparation of capsaicin, but excluding clinical trials involving SB705498 due to its distinct mecha nism as a TRPV1 antagonist. Outcome measures were categorized as continuous or binary. Continuous variables, such as total nasal symptom scores (TNSS) and visual analog scale (VAS) scores, were analyzed using standardized mean difference to account for variations in scoring standards. Binary variables, reporting therapeutic responders, were analyzed using odds ratios. The primary outcomes of this study included TNSS, VAS scores, and the proportion of therapeutic responders. Sec ondary outcomes encompassed a broader range, including substance P (SP) levels, gene expression analysis (TRPV1, PGP9.5, TRPA1, TRPV4, TRPM8, and c-KIT), nasal hyper reactivity, nasal mucosal potential, and time to first relief. PubMed, ClinicalTrials, MedlinePlus, and the Cochrane Library were consulted for related articles published in English. For instance, a search query (rhinitis[Title]) AND (capsaicin[Title/Abstract]) was employed on PubMed. Key words like “capsaicin for rhinitis” were used on websites lacking advanced search functionalities. Additional relevant articles were discovered in reviews within this field to pro vide a more thorough description of the disease. The selection process involved a two-stage approach: initial manual screening by the primary author followed by fur ther refinement using Endnote software. Two authors inde pendently evaluated studies based on criteria such as study type, relevance, and data type. Discrepancies were resolved through discussion, with a third author designated as an arbi trator if necessary, although this was not required. Data extraction was performed independently by both authors, who meticulously reviewed each included article and extracted relevant information. This data was organized into tables outlining study characteristics, including meth ods, participants, interventions, and outcomes. Discrepan cies in data extraction were resolved through discussion, with a third author serving as an arbitrator if required. The risk of bias in included studies was assessed using the Cochrane collaboration’s tool for randomized controlled tri als. Authors independently appraised studies across various domains, including random sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential bias sources. Disagreements Search Methods for Identification of Studies Data Collection and Analysis

Risk of Bias in Included Studies

All the included studies were evaluated using Review Man ager, and their biases are depicted in Fig. 2. Additionally, risk of bias summary illustrates the authors' evaluations of each bias item for each individual study.

Effects of Capsaicin Treatment at the End of Studies

VAS or TNSS of each study at the end of the trials were used for analysis for overall effects of capsaicin in analysis and showed the results in Fig. 3 which using standardized mean difference and showed 95% confidence interval. Due to different measure methods of nasal symptoms, random