Multidimensional characterization of allergic rhinitis in Mysuru, South India: A cluster-based approach

Background: Allergic rhinitis (AR) affects approximately 10% of Indian adults, but its clinical and biological heterogeneity remains poorly defined. Objective: We sought to characterize AR phenotypes in South Indian adults using clinical features, spirometry, fractional exhaled nitric oxide (Feno), skin prick tests, blood biomarkers, and cluster analysis. Methods: This was a prospective observational study of 122 patients (≥18 years old) with AR with or without asthma attending a South Indian tertiary allergy clinic and 50 asymptomatic nonatopic control subjects. Participants underwent standardized symptom/exposure assessments, spirometry, Feno, blood counts, serum IgE, and skin prick tests to 10 aeroallergens. Principal component analysis, correlation networks, and unsupervised k-means clustering were applied to define phenotypes. Results: (Bermuda pollen), and cockroach. Conclusions: This study showed 3 distinct AR clusters with high dust mite sensitization alongside cosensitization with cockroach, weed, and Bermuda pollens. Multicenter studies are warranted to further refine AR clusters, including tissue-level biomarker profiling and relevance to pharmacotherapy and immunomodulatory therapies.