What Do We Know about Asthma Triggers? A Review of the Literature

Abstract

Objective. For patients with asthma, exacerbations and poor control can result from exposure to environmental triggers, such as allergens and air particulates. This study reviewed the international literature to determine whether a global checklist of common asthma triggers might be feasible for use as a research or management tool in clinical practice. Methods. Literature published from 2002 to 2012 was identified through PubMed and EMBASE using the following search terms: asthma, asthma triggers, prevalence, among others. A total of 1046 abstracts were found; 85 articles were reviewed covering six continents (number of articles): Africa (1), Asia (22), Australia (1), Europe (27), North America (22), and South America (4). Results. The literature consistently pointed to asthma triggers as one contributor to poor asthma control. Frequently cited triggers were similar across countries/regions and included allergens (particularly pollens, molds, dust, and pet dander), tobacco smoke, exercise, air pollutants/particulates, weather patterns/changes, and respiratory infections. Definitions of asthma triggers, how triggers are taken into account in definitions of asthma control, and scientific inquiry into optimal management techniques for triggers were inconsistent and sparse. Conclusions. Given the apparent importance of triggers in attaining and maintaining asthma control, empirical research concerning optimal trigger management is needed. Results demonstrate that asthma triggers are similar across continents, suggesting a global checklist of triggers for use in research and clinical practice would be feasible.

• control
• exacerbate
• exacerbations
• international perspective
• review

Acknowledgment

The authors acknowledge Dr. Nancy Kline Leidy for her review and input into the content of this manuscript.

Declaration of Interest

This article was supported by GlaxoSmithKline.

Professor Chapman received support from the GSK-CIHR Research Chair in Respiratory Health Care Delivery at the University Health Network, Toronto, Canada.

Notes

¹ Search terms included asthma + terms related to triggers (trigger, allergen, risk factor, etc.) + incidence or prevalence.

² Search terms included asthma + trigger terms + terms related to coping strategy (avoidance, behavior modification, etc.)