The relationship of nasal mucus properties and symptoms in allergic and acute non-allergic rhinitis

Background: Allergic rhinitis (AR) and acute non-allergic rhinosinusitis (ARS) often present with similar symptoms. While these are generally differentiated by history and occasionally by secretion cell counts, there are few data temporally comparing these conditions.

Methods: A prospective, observational study was conducted to assess nasal mucus properties, nasal obstruction, nasal secretion cells, and health related QOL during the acute phase (Day 5) and during a later phase of illness (Day 14/28). We screened 280 patients and enrolled 42 subjects (ARS, n = 34; and AR, n = 8) who were otherwise healthy and met eligibility criteria. Nasal secretions for cell count and rheology, and acoustic rhinometry were measured on days 5 and 14 of symptoms. SNOT-20 was administered on Day 5, 14, 10 and 28.

Results: In subjects with ARS, there was significantly improved SNOT-20 and major symptom score at day 28 in association with increased nasal cavity volume by acoustic rhinometry and decreased mast cells; all consistent with improvement. However, in subjects with AR there was no symptomatic improvement or change in nasal volume and although there were fewer mast cells and epithelial cells, there was no decrease in the number of eosinophils, neutrophils, or goblet cells in secretions. There was no change in in vitro secretion mucociliary clearability in either group, although values were normal at baseline.

Conclusions: These results suggest that nasal symptoms in ARS are improved over 14-28 days with the reduction of mast cells, and increased nasal volume, while in AR, symptoms persist.