Oral corticosteroid-dependent asthma: current knowledge and future needs.

PURPOSE OF REVIEW: To discuss the current use of oral corticosteroids (OCS) as a chronic treatment in patients with severe asthma and as a rescue treatment for patients presenting with acute exacerbations. RECENT FINDINGS: Airways disease is responsible for the bulk of OCS use in the community and considerable OCS-associated morbidity. I speculate that the key mechanism leading to a beneficial effect in these situations is depletion of circulating eosinophils resulting in a reduced response to potentially inhaled corticosteroid unresponsive recruitment signals to the airway mucosa. This effect is shared by anti-IL-5 biological agents, which have emerged as highly effective OCS-sparing agents. Mitigation of the adverse effects of OCS might also result from a better appreciation of features associated with a response to OCS and targeted, biomarker-directed use. SUMMARY: Longer term, there are real prospects that chronic and acute OCS use in asthma will be replaced by biological agents targeting eosinophilic airway inflammation more specifically and safely.