Can nasal nitric oxide be a biomarker to differentiate allergic and non-allergic rhinitis?

Abstract Background Nasal nitric oxide (nNO), a noninvasive indicator for eosinophilic airway inflammation, has not been adequately studied in different types of rhinitis. The aim this study was to compare nNO levels between allergic (AR) and non-allergic rhinitis (NAR). Patients were included based on their chronic nasal symptoms. Total symptoms score (TNSS) evaluated. measured transnasally with flow 5 ml/s from the nostril an NO analyzer (NIOX MINO; Aerocrine, Sweden). Results evaluated as parts per billion (ppb). Four hundred forty-three patients (277 F/166 M)—337 AR (76%) 106 NAR (24%)—were assessed. had significantly higher TNSS, more severe disease, longer duration disease compared group. Allergic than (370 ppb vs 290 ppb) ( p = 0.001). Likewise, significant differences observed female gender, BMI ≥ 25 kg/m 2 those without sinusitis two groups. When further comorbid asthma, w/o asthma highest TNSS level < NAR+A group, longest rhinitis, older lowest Conclusions This showed that NAR. Although there is no recommended standard threshold nNO, confirmed utility differentiating addition its known fast non-invasive advantages.