title: Smoking and asthma.
abstract: BACKGROUND
  The purpose of this review is to describe the current understanding of the prevalence and adverse effects of cigarette smoking and secondhand smoke (SHS) in asthmatics in terms of patient outcomes and response to inhaled corticosteroids.
  
  
  METHODS
  We searched the English biomedical literature via PubMed, Embase, and Scopus using the terms "smoking and asthma," "secondhand smoke and asthma," "environmental tobacco smoke and asthma," and "smoking/secondhand smoke and corticosteroids." We also reviewed reference lists of identified articles for relevant citations.
  
  
  RESULTS
  In asthmatic patients who smoke, disease control is poorer than in asthmatic nonsmokers. Of all forms of SHS, maternal exposure seems to have the largest impact on asthma by increasing the frequency and severity of the disease and decreasing lung function. Asthmatic children exposed to multiple household smokers face an increased risk for respiratory illness-related absences from school, and these effects persist during adolescence but weaken during adulthood. Airway mucosal permeability is increased in smokers, which could lead to increased clearance of inhaled corticosteroids from the airways. Smokers also have decreased histone deacetylase activity, which is necessary for corticosteroids to fully suppress cytokine production, and can lead to corticosteroid resistance.
  
  
  CONCLUSIONS
  Cigarette smoking and SHS in asthmatics lead to detrimental effects in patient outcomes and effectiveness of steroid therapy.
authors.affiliation: Department of Clinical Pharmacy, Texas Tech University Health Science Center, Dallas, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Stapleton
authors.forename: Amanda
authors.initials: A
authors.lastname: Howard-Thompson
authors.forename: Christa
authors.initials: C
authors.lastname: George
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hoover
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Self
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology*; D016001:Confidence Intervals; D004351:Drug Resistance; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D013714:Tennessee / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D017211:Treatment Failure
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D014028:Tobacco Smoke Pollution