Pediatric Asthma

Asthma is a chronic inflammatory disease of the airways that is characterized by reversible airway obstruction, airway hyperresponsiveness to stimuli, variable airway resistance and flow rates, and transient increases in lung volume. Classic symptoms include cough, wheezing, dyspnea, and chest tightness [1]. Worldwide, asthma prevalence is increasing, with generally higher prevalence rates in westernized societies, English-speaking countries, and developing countries as they become urbanized [2]. In 2002, over 30 million people in the United States had ever been diagnosed with asthma during their lifetime [3]. Asthma is the most common chronic disease in children, affecting 9 million patients younger than 18 years in 2002 [4]. Sixty percent of people who have asthma experienced an exacerbation in the previous year; 4 million of these patients were children [3]. While death due to asthma is rare in children, 187 patients younger than 18 years died from asthma in 2002 [3]. These statistics have equally significant socioeconomic correlates. In the United States, the total cost of asthma in 2002 was $14 billion, $9.4 billion attributed to direct costs (expenses generated in the disease’s prevention, treatment, and rehabilitation) and $4.6 billion to indirect costs (value of resources lost as a result of time absent from work or other usual daily activity as a result of illness) [5]. Medications are now the largest component of direct costs, surpassing costs of inpatient hospitalization [6]. However, children had close to 200,000 hospitalizations in 2002 for asthma, mostly in those younger than 5 years [3]. On average, children with asthma miss more days of school per year compared to their classmates without asthma, with 14.6 million missed days in 2002 at a cost of $1.4 billion [5]. Children were seen in 13.9 million outpatient visits and over 700,000 emergency department (ED) visits for asthma [3]. The ED visit rate for asthma was highest among children younger than 5 years [3]. Societal differences among children with asthma exist as well, with children of poor families more likely to have ever been diagnosed with asthma and more non-Hispanic black children diagnosed with asthma versus non-Hispanic whites and Hispanics [4]. Prior to 1980, asthma was considered a disease of airway