Methods: Thirty-six symptomatic seasonal allergic rhinitis patients (25 male, median age 31 years) were instructed to treat their bothersome symptoms locally with intra-nasal xylometazoline and/or azelastine and/or mometasone, or, if symptoms persevered, with oral bilastine or prednisone. Patients were randomized to “seal” the effect of each local application with one puff of either HPMC or placebo (lactose powder). They completed diaries with symptom scores (0-3), and medications (1 score for any drug application). Objective measurements of Peak Nasal Inspiratory Flow (PNIF), measure of the level of nasal congestion, and Exhaled Breath Temperature (EBT), surrogate marker of airway inflammation, were made before and after treatment.
Results: Combined Symptom and Medication Scores (CSMS) were significantly (P=0.03) lower in the HPMC group, 90±9 vs. 122±12, (mean ± SEM). Following treatment PNIF increased in the HPMC arm by 60% vs. 31% in the placebo one. The before vs. after treatment differences were in favor of the HPMC for both PNIF (P=0.01) and EBT (P=0.007).
Conclusions: In real life intra-nasal HPMC applied following local rescue medications decreased symptoms and reduced nasal congestion/inflammation in subjects with symptomatic allergic rhinitis.