Pharyngeal pH Probe Findings in Patients with Postnasal Drainage

Background Patients commonly present with complaints of postnasal drainage (PND). This study reports the pharyngeal pH probe findings in patients without rhinitis/rhinosinusitis who present with complaints of PND. Methods This is a prospective study of patients presenting with PND but no historical or endoscopic evidence of rhinitis/rhinosinusitis. Twenty-four-hour pharyngeal pH probe studies were done on 32 consecutive patients and compared with historical controls. Results There were a total of 32 patients with PND (mean age, 54 years) and 51 controls (mean age, 49 years). The proportion of patients with positive pH probe studies was higher in PND (28.1%) versus controls (17.6%) but did not reach statistical significance (p = 0.27). However, when comparing the mean number of pharyngeal acid exposure events, patients with PND had significantly more events (1.6) than controls (0.3; p < 0.002). In addition, the mean acid exposure time was significantly higher in PND (0.18%) versus controls (0.01%; p < 0.004). Conclusion The proportion of patients with PND displaying positive pharyngeal 24 pH probe studies is not significantly greater than controls. However, patients with PND do exhibit a statistically greater degree of pharyngeal acid exposure as compared with controls. Additional research is required to delineate the role of pharyngeal reflux in patients with PND.