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Health Journey Support | Overview of Asthma and Severe Asthma

Asthma is a chronic inflammatory disease that results in the narrowing of the airways in the lungs. Severe asthma is asthma that is uncontrolled despite high-intensity treatment. This brochure provides information describing asthma and severe asthma, including asthma symptoms and triggers.

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Overview Asthma Severe Asthma Hcp Br

Overview of Asthma and Severe Asthma

Asthma is a chronic inflammatory disease that results in the narrowing of the airways in the lungs. This makes it hard to breathe. The narrower the airways are, the less air flows in and out of the lungs. Some of the inflammatory cells involved in asthma include eosinophils and neutrophils. In asthma, the muscles surrounding the airways can become more sensitive to triggers that cause them to constrict. This contributes to airway narrowing and its associated symptoms, which may include chest tightness, shortness of breath, wheezing, and coughing, usually at night or early in the morning if not just exercise induced.1,2

Asthma is a leading chronic illness among children and adolescents. Asthma affects people of all ages, but it usually starts in childhood. Over 25 million people have asthma in the United States, and about 7 million of them are children. Allergic asthma is the most common type of asthma, affecting 60% of those with asthma. Anyone can get asthma, but it is more prevalent among African-Americans and Hispanics.1,3-5

Asthma by the numbers

Every year, asthma accounts for approximately6,7:

  • 1.6 million visits to the emergency department
  • 450,000 hospitalizations
  • 46.7 million absences from work, school, or other activities

Going Deeper

Asthma can range from mild to severe. To better individualize treatment plans for people who have asthma, the condition is further delineated by phenotypes—what can be observed by doctors based on history and physical exam—versus endotypes, which can help determine key sources for a patient's asthma, for instance, what may be a main inflammatory mechanism causing the asthma. Examples of phenotypes include exercise-induced asthma and obesity-related asthma. Examples of endotypes include allergies and aspirin sensitivity.8-11

This chart shows some of the possible phenotypes and endotypes that may pertain to an asthma diagnosis9:



Obesity-related asthma

Non-eosinophilic asthma, or neutrophilic asthma (absence of inflammatory eosinophilic cells)

Exercise-induced asthma

Allergic asthma

Adult-onset asthma

Non-eosinophilic asthma, or neutrophilic asthma (absence of inflammatory eosinophilic cells)

Eosinophilic (inflammatory cell type) asthma

Allergic asthma Aspirin-sensitive asthma

Asthma Triggers

Many factors can trigger or worsen asthma symptoms. Exposure to common everyday things that can put an asthma patient at risk include12:

  • Allergens from dust, animal fur, cockroaches, mold, and pollen
  • Irritants such as cigarette smoke, air pollution, chemicals, including those found in home-décor products and cleaning sprays
  • Medicines such as aspirin, nonsteroidal anti-inflammatory drugs, and nonselective beta blockers
  • Upper respiratory infections, such as colds, sinus infections, and ear or throat infections
  • Physical activity, including exercise
  • Conditions such as sleep apnea13
  • Sulfites found in foods and drinks

Severe Asthma

Severe asthma is asthma that is uncontrolled despite high-intensity treatment. Only about 5% of people with asthma have severe asthma, but it accounts for 68% of asthma's medical costs.14,15

Up to 50% of people with severe asthma could have elevated eosinophil levels in the lungs, which can cause inflammation. These inflamed airways can cause severe asthma attacks. Repeated inflammation and attacks can lead to even more attacks and harm the lungs. Signs of severe asthma, including eosinophilic asthma, include frequent use of a rescue inhaler, waking up at night due to asthma symptoms, having to take oral steroids for asthma flare-ups, and having asthma attacks that require emergency care.16-21

References: 1. National Heart, Lung, and Blood Institute. What is asthma? Accessed November 15, 2017. 2. Sampson AP. The role of eosinophils and neutrophils in inflammation. Clin Exp Allergy. 2000;30(Suppl1):22-27. 3. Asthma and Allergy Foundation. Allergens and allergic asthma. Accessed November 15, 2017. 4. United States Environmental Protection Agency. Asthma facts. files/2016-05/documents/asthma_fact_sheet_english_05_2016.pdf. Accessed November 16, 2017. 5. Centers for Disease Control and Prevention. Asthma in schools. https://www.cdc. gov/healthyschools/asthma/. Accessed November 16, 2017. 6. Centers for Disease Control and Prevention. National surveillance of asthma: United States, 2001-2010. https://www.cdc. gov/nchs/data/series/sr_03/sr03_035.pdf. Accessed November 16, 2017. 7. Centers for Disease Control and Prevention. Most recent asthma data. recent_data.htm#modalIdString_CDCTable_0. Accessed November 16, 2017. 8. Lötvall J, Akdis CA, Bacharier LB, et al. Asthma endotypes: a new approach to classification of disease entities within the asthma syndrome. J Allergy Clin Immunol. 2011;127(2):355-360. 9. Skloot GS. Asthma phenotypes and endotypes: a personalized approach to treatment. Curr Opin Pulm Med. 2016;22(1):3-9. 10. How is asthma diagnosed? Accessed November 28, 2017. 11. Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention, 2017. Accessed November 15, 2017. 12. National Heart, Lung, and Blood Institute. What are the signs and symptoms of asthma? Accessed November 21, 2017. 13. Alkhalil M, Schulman E, Getsy J. Obstructive sleep apnea syndrome and asthma: what are the links? J Clin Sleep Med. 2009;5(1):71-78. 14. American Academy of Allergy, Asthma and Immunology. The prevalence of severe refractory asthma. JACI-In-Practice/refractory-asthma. Accessed November 15, 2017. 15. Casciano J, Krishnan J, Dotiwala Z, et al. Clinical and economic burden of elevated blood eosinophils in patients with and without uncontrolled asthma. J Manag Care Spec Pharm. 2017;23(1):85-91. 16. Chung KF, Wenzel SE, Brozek JL, et al. International ERS/ATS guidelines on definition, evaluation and treatment of severe asthma. Eur Respir J. 2014;43(2):343-373. 17. De Groot JC, Ten Brinke A, Bel EH. Management of the patient with eosinophilic asthma: a new era begins. ERJ Open Res. 2015;1(1). pii:00024-2015. 18. Trivedi SG, Lloyd CM. Eosinophils in the pathogenesis of allergic airways disease. Cell Mol Life Sci. 2007;64(10):1269-1289. 19. Coumou H, Bel EH. Improving the diagnosis of eosinophilic asthma. Expert Rev Respir Med. 2016;10(10):1093-1103. 20. National Heart, Lung, and Blood Institute. Expert panel report 3: guidelines for the diagnosis and management of asthma. Accessed November 21, 2017. 21. Wenzel S. Severe asthma in adults. Am J Respir Crlt Care Med. 2005;172(2):149-160.