title: 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.
authors.affiliation: United BioSource Corporation, London, UK. margaret.vernon@unitedbiosource.com
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Vernon
authors.forename: Ingela
authors.initials: I
authors.lastname: Wiklund
authors.forename: Jill A
authors.initials: JA
authors.lastname: Bell
authors.forename: Peter
authors.initials: P
authors.lastname: Dale
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Chapman
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects; D000485:Allergens / Q000009:adverse effects; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology / Q000276:immunology; D004777:Environment; D015444:Exercise; D014943:Global Health; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology; D052638:Particulate Matter / Q000009:adverse effects; D012141:Respiratory Tract Infections / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects; D014887:Weather
chemical_list: D000393:Air Pollutants; D000485:Allergens; D052638:Particulate Matter; D014028:Tobacco Smoke Pollution