Appropriate use of oral corticosteroids for severe asthma.

Severe asthma represents a significant burden of disease, particularly in high income nations; oral corticosteroids (OCS) remain an important part of the management toolkit for these patients. Corticosteroids are effective at targeting numerous elements of the type 2/eosinophilic inflammatory pathway and lead to both rapid reduction in eosinophilic inflammation and longer term reduction in airway hyper-responsiveness. Resistance or insensitivity to corticosteroids is a feature of severe asthma, with persistent type 2 inflammation often occurring despite regular use of OCS. OCS remain the only accepted, effective treatment for acute asthma, and also continue to play an important role in the long term management of severe asthma, in spite of their significant side effect profile. Even with the availability of the new biological therapies against IgE and interleukin-5, it is likely that a large proportion of patients will continue to require OCS to control their asthma. Future work should focus on optimising the balance between OCS efficacy and safety, and continued development of agents that allow reduction, or ideally discontinuation of their use, is needed.