Background Allergic rhinitis (AR) is a chronic inflammatory condition affecting the nasal mucosa, commonly triggered by environmental allergens. Altered nasal pH may impact mucociliary function and local immunity. Objective To evaluate the pH of nasal secretions and analyze its variability among patients with allergic rhinitis using digital pH meters and colorimetric strips. Methods A prospective cross-sectional study was conducted over six months at a tertiary hospital in Tamil Nadu. Seventy-three patients diagnosed with AR based on clinical criteria were recruited. Nasal pH was measured using a calibrated digital pH meter and validated strips. Variability in pH values was analyzed with respect to symptom severity and patient characteristics. Results The mean nasal pH was Alkaline pH (>7.4) was observed in 41.1% of patients, neutral pH (6.8–7.0) in 42.5%, and mildly acidic pH (<6.8) in 16.4%. Alkaline pH values were more frequently associated with nasal congestion and sneezing, although this correlation was not statistically significant. Conclusion Nasal pH variability is evident in AR, with a trend toward alkalinity among symptomatic individuals. Nasal pH may serve as a non-invasive physiological marker of disease activity.

.