Asthma phenotypes: an approach to the diagnosis and treatment of asthma.

I teach that "Asthma is the most treatable of all chronic diseases known to mankind." Yet, outcome data from throughout the world (emergency department visits, hospitalizations, and quality of life) indicate that the diagnosis and treatment of asthma are not optimal and need improvement. Why? First, asthma is not thought of as a complex, heterogeneous disease or syndrome that consists of different phenotypes and endotypes. Second, asthma is variable, particularly in its severity, and is influenced by known, unknown, avoidable, and unavoidable environmental factors. Third, treatment usually requires complex inhalational devices that are difficult to understand and use, and with which adherence is suboptimal. Continued education on how to appropriately use medications, particularly inhaled medications, is absolutely essential, and knowledge and access to a backup treatment plan to be initiated by the patient for an asthma flare is necessary. Fourth, assessment of asthma is primarily based on symptoms, and, at times, all symptoms are due to asthma, but many times some or all symptoms are due to unrecognized and untreated comorbid or coexisting conditions. Too often, asthma is viewed as a disease that occurs in isolation, and comorbid and coexisting conditions are not appropriately identified and treated. Allergists/immunologists are well suited to provide the type of comprehensive care required to optimize asthma outcomes for the benefit of individual patients and society.