Nasal nitric oxide is a useful biomarker for acute unilateral maxillary sinusitis in pediatric allergic rhinitis: A prospective observational cohort study

Abstract Background Nasal nitric oxide (nNO) could be a biomarker for nasal passage inflammation and sinus ostial patency. We have aimed to investigate the nNO concentration and the effect of antibiotic therapy in children with perennial allergic rhinitis (PAR) children with/without acute bacterial sinusitis. Methods We enrolled a cohort of 90 and 31 children with PAR, without and with acute unilateral maxillary sinusitis, and 79 normal children. Acute bacterial maxillary sinusitis was diagnosed based on clinical signs and symptoms, radiographic examination and nasal fibroendoscopy. Rhinitis control assessment test (RCAT), rhinomanometry, nNO and fractional exhaled NO (FENO) measurements were performed before and 2 weeks after antibiotic therapy. Results We found significantly higher mean nNO levels, FENO values, and total nasal resistance in children with PAR than in normal children ( p  ​ p  ​ p  ​ r  ​= ​0.59, p  ​ r  ​= ​−0.54, p  ​ Conclusions We conclude that the obstruction of NO from the sinus into the nasal passage is the likely explanation for the decreased lesion-side nNO levels in acute unilateral maxillary sinusitis. nNO is a non-invasive biomarker with high sensitivity to diagnose and monitor treatment responses of PAR patients with acute rhinosinusitis. Both nNO and FENO levels return to baseline following antibiotic therapy, supporting the “one airway one disease” concept.