The management of severe asthma in 2020.

Asthma is a chronic inflammatory disease of the airways affecting more than 300 million patients worldwide. The disease can be of various severity ranging from very mild to severe. The severe form of the disease only affects about 5% of patients but is responsible for a large component of the overall disease burden and results in about half of direct asthma-related costs. This led to important investments in research, which allowed better understanding of its pathophysiology and the development of new therapeutic strategies. Despite those breakthroughs, recent guidelines still emphasize the need to distinguish uncontrolled or difficult-to-control asthma from severe asthma. Indeed, a significant number of patients referred to severe asthma clinics are non-severe uncontrolled patients. However, the basics of asthma management such as ensuring that the patient has the right diagnosis, recognition of contributing comorbidities, avoidance of exposure to sensitizing agents in allergic individuals, regular assessment of control, and patient education should not be forgotten. The major improvements in pathophysiology arose from the evidences that asthma is of heterogeneous nature. Such heterogeneity has been particularly studied in severe asthma, leading to the recognition of more homogeneous groups referred to as phenotypes. Appropriate phenotyping of individual patients allows enforcing more specific treatment plans for patients, which is a step toward precision medicine. The high morbidity and socioeconomic burden of severe asthma has led to the development of optimized therapeutic strategies in addition to the commercialization of new drugs. Many of these have targeted the eosinophilic component of inflammatory asthma phenotypes while there is still a need to develop new therapies for non-eosinophilic asthma. When asthma is not controlled by optimal therapy, including a high-dose of inhaled corticosteroid (ICS) and a long-acting beta-agonist (LABA), a long acting anticholinergic agent can be added and if insufficient, a variety of biologic agents is now available in many countries. When biologics are not an option, thermoplasty and macrolides have also become available. Despite many recent breakthroughs in severe asthma, much research needs to be done. Improvement in availability of targeted asthma medications and asthma prevention should be top priorities.