Eosinophil-to-lymphocyte Ratio and Platelet-to-lymphocyte Ratio in Allergic Rhinitis

A growing number of literatures explores the diagnostic role of serum eosinophil-to-lymphocyte ratio (ELR) and platelet-to-lymphocyte ratio (PLR) in patients with allergic rhinitis (AR), yielding variable findings and lacking control of potential confounding variables and standardized cut-offs for clinical application. We aim to clarify their role through a systematic review and meta-analysis. Web of Science, PubMed, Embase, Scopus, Cochrane Central Register of Control Trials, Google Scholar, and Medline were systematically searched up to October, 2025. The search strategy was described by a combination of relevant medical subheadings (MeSH) and keywords. Eligible English language studies were reviewed, and their quality was appraised. This review adhered to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A total of 12 studies, including 3 449 individuals, met the inclusion criteria. AR group had significantly higher ELR (SMD: 0.64) and insignificantly lower PLR (SMD-0.02) than control. Patients with persistent AR had, numerically but not significantly, higher ELR (SMD: 1.19) and PLR (SMD: 0.58) compared to intermittent AR. ELR value of greater than 0.085 had a pooled AUC of 67% in discrimination of patients with AR from control. This AUC rate was statistically significant. This review investigated that no clear correlation was found between mean PLR and AR. However, mean ELR was found to be significantly increased in patients with a diagnosis of AR, and a numerical trend toward higher ELR with greater disease severity was observed. Though further research is necessary to determine its clinical utility.