Efficacy of air purifier therapy for patients with allergic asthma.

OBJECTIVES: This study aimed to evaluate the efficacy of air purifier therapy for patients with allergic asthma. METHODS: Thirty-eight subjects were categorized under two groups namely treatment group and control group. All subjects were under 18 years of age and they had been clinically diagnosed with allergic asthma. The treatment group used high efficiency particulate air (HEPA) purifiers for six consecutive months, and the control group did not use the air filters. Particulate matter (PM) data and dust samples (from bedding and a static point) were collected from the subjects' bedrooms before they started using the air purifiers and each month thereafter. Simultaneously, the subjects were asked to complete a questionnaire for the Asthma Control Test (ACT) or Childhood Asthma Control Test (C-ACT). Fractional exhaled nitric oxide (FENO) tests were performed at the start and end of the study. The concentrations of Der p1 and Der f1 were measured in the dust samples. RESULTS: (1) After utilizing the air purifier, the concentrations of house dust mite (HDM) allergens (Der p1+ Der f1) in the dust samples decreased. In addition, the PMindoor/outdoor values significantly decreased. (2) The ACT and C-ACT scores in the treatment group maintained a steady significant upward trend. (3) At the end of the study, the FENO levels in both groups were lower, although the differences were not significant. CONCLUSIONS: It is witnessed that HEPA air purifiers can decrease indoor HDM allergen and PM levels and improve the quality of life for allergic asthma patients.

Efficacy of air purifier therapy in allergic rhiniti.

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). PM1.0indoor/outdoor, PM2.5indoor/outdoor, PM10indoor/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.