Because it divides the nasal breathing cycle into dis- crete sets of points, traditional rhinomanometry may provide an incomplete picture of the cycle.63 Four-phase rhinomanometry may be a more naturalistic method of measuring nasal breathing, as it permits accurate as- sessment of the pressure–flow relationship during the cycle.64 This methodology was employed by Meltzer et al63 in a 14-day, placebo-controlled study of deslorata- dine 5 mg/d in 220 subjects (59% female, 41% male; mean age, 32 years [range, 18–58 years]) with a ≥2-year history of SAR. The treatment response was assessed by investigators and subjects on day 15. Airflow during the descending expiratory phase was significantly greater with desloratadine compared with placebo (P = 0.046), and the percentage increase in total in- spiratory nasal airway resistance was significantly lower (0.5% vs 15.1%, respectively; P = 0.03). Subject- and investigator-rated reflective TNSS (including nasal congestion) was significantly decreased with deslorata- dine compared with placebo (–2.7 vs –1.9; P = 0.02).