The Expert Panel Report #2 defines asthma as a chronic inflammatory disorder of the airways (NIH 1997, 1999). In susceptible individuals, the inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation causes an increase in the asthmatic's bronchial hyperresponsiveness to a variety of stimuli.
Asthma prevalence, severity, and mortality are higher in females than males in the United States (CDC 1998, 2003; Tarwick, Holm, and Wirth 2001; Ford et al. 2001). The burden from asthma in the United States has increased over the past twenty years (CDC 2002b; CDC 2003; Fuhlbrigge et al. 2002). In 2001, 31 million people were diagnosed with asthma during their lifetimes; 20.3 million had asthma at the time of interview, that is, current prevalence. Twelve million asthmatics, 60 percent of those who had asthma at the time of the survey, had experienced an asthma attack in the previous year (CDC, NCHS 2003). Females had a 10 percent higher rate for lifetime asthma, a 30 percent higher rate of current asthma, and a 40 percent higher asthma attack prevalence than males (CDC, NCHS 2003). The CDC considers asthma attack prevalence to be an indicator of patients with suboptimal asthma control at risk for poor asthma outcome (CDC, NCHS 2002, 2003). African Americans had higher prevalence rates than whites and Hispanics (CDC, NCHS 2002, 2003).
The report cited atopy, the genetic predisposition for the development of an IgE mediated response to common airborne allergens, as the most important predisposing factor for developing asthma. Emphasis was placed on periodic monitoring of symptoms and using portable peak flow meters to assess lung function. Efforts to reduce factors that contribute to asthma severity were recommended, including avoidance of exposure to tobacco smoke and treatment of co-morbid