Asthma overview
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Editor(s)-in-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-632-7753; Philip Marcus, M.D., M.P.H. [2]
Overview
Approximately 5% of the population have been diagnosed with asthma and affects one in four urban children.[1][2] Asthma is a chronic inflammatory disease that is characterized by a hyper-responsive airway and a resultant reversible airway obstruction. Asthmatics, as a response to one or more triggers develop intermittent airway constriction and subsequent inflammation that is lined with excessive amounts of mucus. Environmental stimulants such as dust, cold air, mold, pollen and exercise or stress can trigger an asthmatic episode; however, in children, viral illness such as common cold remains the most common trigger.[3] The classic symptoms include prolong expiratory wheeze, cough and shortness of breath secondary to airway obstruction that promptly responds to bronchodilator therapy. Between episodes, most patients remain asymptomatic or have mild symptoms and may remain short of breath for longer periods after exercise. A positive bronchodilator response is strongly suggestive of asthma. Short-acting beta-2 agonist, inhaled anti-cholinergics and systemic steroids may be used for immediate symptomatic relief; however, long-term symptom control may be achieved with long-acting beta-2 agonists, mast cell stabilizers, leukotriene inhibitors and/or steroids.
Epidemiology and Demographics
Approximately 300 million people around the world currently have asthma[4] and the number is estimated to increase by additional 100 million by the year 2025. Prevalence of asthma is high among children and females in industrial nations. International Study of Asthma and Allergies in Childhood (ISAAC) which measured the global prevalence and severity of asthma symptoms in children demonstrated that the high rates of asthma were noted in countries whose predominant language is English[5]. Puerto Rican people have the highest prevalence of asthma in USA[6]. Asthma accounts for 217,000 emergency room visits and 10.5 million physician office visits every year[7].
Natural History, Complications and Prognosis
Wheezing may occur early in childhood. But in majority of cases, it may not persist into adulthood unless severe or has predisposition to asthma. Asthma progression during childhood vary with gender and may sometimes regress completely unlike adult onset asthma. Prognosis of asthma in absence of other co-morbidities is generally good with treatment and life expectancy is similar to that of general population. Complications of asthma may include status asthmaticus, respiratory failure, candidiasis and cardiac dysfunction.
Diagnosis
Chest X-ray
Chest x-ray in asthmatics is often normal. But however it is done to exclude other causes of wheeze and in diagnosis of complications such as atelectasis and pneumonia[8].
References
- ↑ Akinbami LJ, Schoendorf KC (2002) Trends in childhood asthma: prevalence, health care utilization, and mortality. Pediatrics 110 (2 Pt 1):315-22. PMID: 12165584
- ↑ Lilly CM (2005) Diversity of asthma: evolving concepts of pathophysiology and lessons from genetics. J Allergy Clin Immunol 115 (4 Suppl):S526-31. DOI:10.1016/j.jaci.2005.01.028 PMID: 15806035
- ↑ Zhao J, Takamura M, Yamaoka A, Odajima Y, Iikura Y (2002) Altered eosinophil levels as a result of viral infection in asthma exacerbation in childhood. Pediatr Allergy Immunol 13 (1):47-50. PMID: 12000498
- ↑ Masoli M, Fabian D, Holt S, Beasley R, Global Initiative for Asthma (GINA) Program (2004). "The global burden of asthma: executive summary of the GINA Dissemination Committee report". Allergy. 59 (5): 469–78. doi:10.1111/j.1398-9995.2004.00526.x. PMID 15080825.
- ↑ Lai CK, Beasley R, Crane J, Foliaki S, Shah J, Weiland S; et al. (2009). "Global variation in the prevalence and severity of asthma symptoms: phase three of the International Study of Asthma and Allergies in Childhood (ISAAC)". Thorax. 64 (6): 476–83. doi:10.1136/thx.2008.106609. PMID 19237391.
- ↑ Akinbami LJ, Moorman JE, Liu X (2011). "Asthma prevalence, health care use, and mortality: United States, 2005-2009". Natl Health Stat Report (32): 1–14. PMID 21355352.
- ↑ Pitts SR, Niska RW, Xu J, Burt CW (2008). "National Hospital Ambulatory Medical Care Survey: 2006 emergency department summary". Natl Health Stat Report (7): 1–38. PMID 18958996.
- ↑ National Asthma Education and Prevention Program (2007). "Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma-Summary Report 2007". J Allergy Clin Immunol. 120 (5 Suppl): S94–138. doi:10.1016/j.jaci.2007.09.043. PMID 17983880.