The diagnosis of asthma, a clinical syndrome.

Clinical experience and now genetic data indicate that asthma is a heterogeneous clinical syndrome--clinical cases emerge, proceed and respond to treatments in different ways. Currently the diagnosis of asthma (as enunciated in national guidelines) is based on incisive clinical methods, supported by lung function testing that substantiates labile or reversible bronchial airflow obstruction. But this approach alone is insufficient to address the diagnostic and therapeutic challenges presented by asthma's heterogeneity. This article contends that bronchial pathology (with molecular and morphologic analysis) should be adopted into the mainstream clinical practice of asthma so as to clarify the nature of the bronchial disorder in compliant patients not settling securely on moderate-dose inhaled corticosteroid. This would allow a differentiated approach to appropriate therapeutics--those already available and those yet to be developed.