November 2011

Asthma is a chronic inflammation of the airways with reversible episodes of obstruction, caused by an increased reaction of the airways to various stimuli. Asthma breathing problems usually happen in "episodes" or attacks but the inflammation underlying asthma is continuous.

• Asthma is one of the most common chronic disorders in childhood, currently affecting an estimated 7.1 million children under 18 years; of which 4.1 million suffered from an asthma attack or episode in 2009.¹
  
  
• An asthma episode is a series of events that results in narrowed airways. These include: swelling of the lining, tightening of the muscle, and increased secretion of mucus in the airway. The narrowed airway is responsible for the difficulty in breathing with the familiar "wheeze".
  
  
• Asthma is characterized by excessive sensitivity of the lungs to various stimuli. Triggers range from viral infections to allergies, to irritating gases and particles in the air. Each child reacts differently to the factors that may trigger asthma, including:
  
  
  • respiratory infections, colds
  • allergic reactions to allergens such as pollen, mold, animal dander,
  • feathers, dust, food, and cockroaches
  • exposure to cold air or sudden temperature change
  • cigarette smoke
  • excitement/stress
  • exercise
• Secondhand smoke can cause serious harm to children. An estimated 400,000 to one million asthmatic children have their condition worsened by exposure to secondhand smoke.²
  
  
• Asthma can be a life-threatening disease if not properly managed. In 2007, 3,447 deaths were attributed to asthma. However, deaths due to asthma are rare among children. The number of deaths increases with age. In 2007, 152 children under 15 died from asthma compared to 659 adults over 85.³
  
  
• Asthma is the third leading cause of hospitalization among children under the age of 15. Approximately 32.7 percent of all asthma hospital discharges in 2006 were in those under 15, however only 20.1% of the U.S. population was less than 15 years old.⁴
  
  
• In 2005, there were approximately 679,000 emergency room visits were due to asthma in those under 15.⁵
  
  
• Current asthma prevalence in children under 18 ranges from 4.6% in Idaho to 13.9% in the District of Columbia.⁶
  
  
• Since 1999, mortality and hospitalizations due to asthma have decreased and asthma prevalence had stabilized, although it now appears to be increasing.
  
  
• Asthma medications help reduce underlying inflammation in the airways and relieve or prevent airway narrowing. Control of inflammation should lead to reduction in airway sensitivity and help prevent airway obstruction.
  
  
• Two classes of medications have been used to treat asthma -- anti-inflammatory agents and bronchodilators. Anti-inflammatory drugs interrupt the development of bronchial inflammation and have a preventive action. They may also modify or terminate ongoing inflammatory reactions in the airways. These agents include inhaled corticosteroids, cromolyn sodium, and other anti-inflammatory compounds. A new class of anti-inflammatory medications known as leukotriene modifiers, which work in a different way by blocking the activity of chemicals called leukotrienes that are involved in airway inflammation have recently come on the market.
  
  
• Bronchodilators act principally to dilate the airways by relaxing bronchial smooth muscle. They include beta-adrenergic agonists, methylxanthines, and anticholinergics.
  
  
• The annual direct health care cost of asthma is approximately $50.1 billion; indirect costs (e.g. lost productivity) add another $5.9 billion, for a total of $56.0 billion dollars.⁷
  
  
• Asthma is one of the leading causes of school absenteeism;⁸ in 2008, asthma accounted for an estimated 14.4 million lost school days in children with an asthma attack in the previous year.⁹
  
  

For more information on asthma, please review the Asthma Morbidity and Mortality Trend Report in the Data and Statistics section of our website at www.lung.org or call the American Lung Association at 1-800-LUNG-USA (1-800-586-4872).

Sources:
1 Centers for Disease Control and Prevention: National Center for Health Statistics, National Health Interview Survey Raw Data, 2009. Analysis by the American Lung Association Research and Program Services Division using SPSS and SUDAAN software. 
2 California Environmental Protection Agency: Respiratory Health Effect of Passive Smoking, June 2005.
3 Centers for Disease Control and Prevention. National Center for Health Statistics. Final Vital Statistics Report. Deaths: Final Data for 2007. May 2010. Vol 58 No 19. 
4 Centers for Disease Control and Prevention: National Center for Health Statistics, National Hospital Discharge Survey, 2006. Unpublished data provided upon special request to the NCHS.
5 Centers for Disease Control and Prevention: National Center for Health Statistics, National Hospital Ambulatory Medical Care Survey, 2005. Unpublished data provided upon special request to the NCHS.
6 Center for Disease Control and Prevention: Behavioral Risk Factor Surveillance Survey, 2009. Analysis by the American Lung Association Research and Program Services Division using SPSS and SUDAAN software.
7 Barnett SB, Nurmagambetov TA. Costs of Asthma in the Unites States: 2002-2007. Journal of Allergy and Clinical Immunology. 2011; 127:145-52.
8 Centers for Disease Control and Prevention. National Center for Chronic Disease Prevention and Health Promotion. Healthy Youth! Health Topics: Asthma. August 14, 2009. Accessed on February 9, 2010.
9 Centers for Disease Control and Prevention: National Center for Health Statistics, National Health Interview Survey Raw Data, 2009. Analysis by the American Lung Association Research and Program Services Division using SPSS and SUDAAN software.

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