Abstract
Severe asthma has been increasingly recognized as a heterogenous disease with varied clinical characteristics and pathophysiological processes. Patients with severe asthma suffer significant impairment in their daily life and impose a substantial burden on health care resources. The recent work of consortia groups has led to an improved definition of severe asthma as well as better characterization of the patients with severe disease. Different approaches, including unbiased cluster analyses, have been utilized to identify severe asthma phenotypes (subgroups) defined by their clinical characteristics and immune processes. Recognition of severe asthma phenotypes has assisted the development of targeted therapies by identifying patients more likely to respond to the specific agent. In this article, we discuss the evolution of our understanding of severe asthma and review the currently available therapies and promising drugs in development. In addition, we examine the role of bronchoscopy in severe asthma and the emerging evidence regarding bronchial thermoplasty.