Study Population
Adults (18 years and older) newly referred for chronic rhinitis were consecutively recruited. Patients were included if they had at least two nasal symptoms (either nose block, runny nose, sneezing or itchy nose) for at least three months. These rhinitis patients were grouped into either “Rhinitis with PND” group or “Rhinitis only” group based on presence or absence of PND symptoms. Patients were excluded if there was a previous history of nasal surgery, who has underlying systemic condition that affect the nasal mucosa such as autoimmune diseases, Wegener’s Granulomatosis, Cystic Fibrosis, Systemic Lupus Erythematosus. Pregnant patient, recent URTI/nasal infections, patients who have chronic rhinosinusitis with nasal polyps and nasal tumors are also excluded.
All recruited patients underwent assessment for rhinitis and scored the severity of their nasal symptoms for the past 1 week using the visual analogue score (0-100mm). They were defined to have allergic rhinitis if there was suggestive history (presence of a trigger, other allergic comorbidities, family history) supported by either a positive skin prick test or serum specific immunoglobulin E towards aeroallergens.