DEFINITION AND IMPACT OF ASTHMA Asthma is a chronic inflammatory disorder of the airways involving numerous cell types and mediators. Patients with asthma exhibit variable and recurring symptoms, including recurrent episodes of cough or wheeze, breathlessness, and chest tightness (National Asthma Education and Prevention Program [NAEPP], 2007). The airflow obstruction responsible for the symptoms is largely reversible and related to bronchial smooth muscle contraction (bronchoconstriction), inflammation of the airway mucosal surface leading to edema and increased mucus production, and hyperresponsiveness or increased bronchial reactivity. Asthma is unique because it has a significant direct impact on people across the continuum of life, from the young to the very old. It is a leading diagnosis among children and is associated with significant morbidity as measured in exacerbations, missed days of school, and decreased quality of life. According to national statistics, more than 20 million people in the United States have asthma, including 9 million children and adolescents (American Lung Association, 2005; Dey, Schiller, & Tai, 2004). In other surveys, nearly 12% of children report an asthma diagnosis, and the prevalence is disproportionately higher among lower socioeconomic groups (Bloom & Dey, 2006; Cloutier, Hall, Wakefield, & Bailit, 2005). Children experience 4 million asthma attacks annually, and 44% of hospitalizations for this disease occur in children (Hall & Owings, 2002). In 2002, 14.7 million days were missed from school reportedly due to asthma. Diagnosis is challenging in young children who often present with transient