 Asthma is an inflammatory condition of the airways in the lungs that results in obstruction of airflow in those with the condition. The disease continues to be a major worldwide health care problem and its prevalence continues to increase annually. In 2005, 20 million people were diagnosed with asthma. The disease causes significant morbidity and accounts for 5,000 deaths annually. Between 1980 and 1994 the prevalence of asthma increased 74 in the United States and, in children under age 5, the prevalence increased by 160. The allergic etiology of airway inflammation associated with asthma is established. Bronchial washings of asthmatic subjects are most often characterized by eosinophils, mast cells, and cytokines that are associated with the Th2 allergic phenotype. Similarly, IgE plays a pivotal role in airway inflammation of asthmatic subjects when allergens that cross-link IgE bound to mast cells in the airways cause the release of histamine and other inflammatory mediators. The association of asthma and the IgE mediated allergic phenotype is well established and up to 70 of asthmatics also suffer from allergic disease. 