Efficacy of air purifier therapy in allergic rhinitis

Background: With the rising prevalence of allergic rhinitis, the utility of indoor environmental management deserves increasing scrutiny. This research aims at evaluating the ability of air purifiers to be a therapy of allergic rhinitis. Methods: 32 subjects (25 +/- 13.5 years old) diagnosed with allergic rhinitis were selected and HEPA air purifiers placed in their bedrooms for 4 months. Before the intervention and each month, dust samples were collected with a vacuum cleaner and the dust collector assessed for allergen content. Additionally, static dust collectors were left in place all month to collect dust by sedimentation. Particulate matter (PM) was assessed in terms of PMindoor/outdoor ratios. The Rhinitis Quality of Life Questionnaire (RQLQ) was used to assess symptoms. Results: Der p 1(78 (30, 82) ng/g) was the dominant dust mite allergen in air samples of patients' bedroom as well as static collections. Der f1 (444 (345, 667) ng/g) was the dominant allergen in bedding. Der f1 levels in both air and bed sampling significantly decreased after initiation of HEPA air purifiers (P < 0.05). PM1.0(indoor/)(outdoor) PM2.5(indoor/)(outdoor) PM10(indoor/)(outdoor) all decreased (P < 0.001) with the HEPA filtration intervention. According to RQLQ data, HEPA filtration was associated with improvements in activity limitation, non-nasal-eye symptoms, practical problems, and nasal symptoms (P < 0.001). Conclusion: HEPA air purifiers can effectively reduce PM and HDM allergen concentration in the indoor air, and thereby improve clinical manifestations of patients with AR.