Effect of continuous positive airway pressure on allergic rhinitis in patients with obstructive sleep apnea–hypopnea syndrome

BACKGROUND: The effect of continuous positive airway pressure (CPAP) on nasal symptoms in patients with obstructive sleep apnea–hypopnea syndrome (OSAHS) remains controversial. In addition, possible mechanism(s) remains unclear. OBJECTIVE: To examine whether CPAP contributes to the onset and exacerbation of allergic rhinitis (AR) in OSAHS patients based on patient-reported changes in nasal symptoms with and without CPAP therapy and the detection of house dust mites (HDMs) in CPAP filters and household environments. MATERIALS AND METHODS: In a cohort of OSAHS patients, 350 patients who were undergoing CPAP therapy and 100 patients who declined CPAP therapy were retrospectively analyzed. These patients were contacted by telephone and asked to compare their nasal symptoms before and after CPAP therapy. HDMs in air conditioner and CPAP device filters and in household dust samples were detected using enzyme-linked immunosorbent assays. RESULTS: The prevalence of AR was higher in the CPAP group vs the non-CPAP group (15.8% vs 7.0%, respectively; P = 0.025). The onset of AR among the OSAHS patients with no previous history of AR significantly increased within the first year of CPAP therapy compared with the control group (5.7% vs 0%, respectively; P = 0.031). Meanwhile, the patients with a history of AR were more likely to experience exacerbated rhinitis symptoms within the second year of treatment compared with the control group (7.5% vs 0%, respectively; P = 0.005). There was no significant difference in HDM concentrations between the CPAP and air conditioner filters, yet the concentrations in both the filters were higher than the concentrations in the bedroom dust samples (all P < 0.05). CONCLUSION: CPAP is associated with the onset and exacerbation of AR in OSAHS patients. Long-term exposure to high concentrations of HDM allergens may be a significant factor.