Purpose of review: To review and interpret recent literature related to the role of environmental control in prevention and treatment of asthma.
Recent findings: Environmental control has a clearly established role in the management of asthma, but its role as a primary prevention tool is not supported by recent clinical trials. Although some of the interventions tested in these trials reduced the risk of asthma, the interventions often included dietary modification and those trials intervening only on environmental exposures were largely negative. Environmental interventions that target multiple asthma triggers, such as a laminar airflow device and relocation to high altitude, continue to demonstrate efficacy in asthma. Several studies highlight the efficacy of portable HEPA purifiers in reduction of indoor particulate matter and improving asthma outcomes. Several recently published practice parameters provide evidence-based recommendations for environmental control practices targeting furry pet, rodent, and cockroach allergens. Emerging work highlights the potential impact of spatial-temporal aspects of exposure and the shape of the dose–response relationships on the indoor allergen exposure-asthma relationship.
Summary: Environmental interventions likely have no effect on the risk of developing atopic disease, but multifaceted interventions are generally of benefit in the management of asthma, particularly in children.