Environmental intervention for house dust mite control in childhood bronchial asthma

Abstract

Objectives: This study was carried out to determine the effectiveness of physical and chemical environmental control measures for house dust mites (HDM) in controlling bronchial asthma in children. Methods: A total of 160 asthmatic children who were sensitized to HDM underwent clinical and environmental assessment. The children were randomly allocated into one of four groups according to the intervention (chemical, physical, both chemical and physical, none) and the effectiveness of the intervention was assessed at 8 and 16 weeks. Results: The group for which physical control measures were used showed significant improvement in all outcome measures, including mean differences of forced expiratory volume after 1 s (FEV1) and peak expiratory flow rate (PEFR), which were 2.05% and 4.65 l/min, respectively, at the 8-week follow-up evaluation. The percentage of severe asthma decreased from 45 to 22%. Similar results were obtained for the group with both chemical (tannic acid) and physical interventions (p<0.05 for all measures). In the group where tannic acid was used as a chemical measure, the number of children with moderate and severe asthma decreased from 15 in each category to 11 and 7, respectively. In the control group, only the mean difference of PEFR (1.62 l/min) was significant after 16 weeks. Despite these promising findings, only the FEV1 was significantly different (p = 0.014) when the four groups were compared. Conclusions: Based on these results, we conclude that simple physical control measures have the potential to contribute to the control of asthma symptoms in asthmatic children sensitized to HDM allergen. © The Japanese Society for Hygiene 2012.