[Severe bronchial asthma]

The term 'difficult-to-treat asthma' indicates that the asthma is not sufficiently controlled despite prescription of high doses of asthma medication. The term 'severe asthma' is used when the asthma is still insufficiently controlled after exclusion or treatment of any complicating factors; an important complicating factor is poor compliance. Recent studies have focused on the heterogeneous character of asthma and on the definition of specific phenotypes, with the aim of developing phenotype-specific treatments. Treatment options for severe asthma are only partly evidence based. The decision to implement additional therapy for severe asthma depends on the individual patient, the asthma phenotype, and the adverse-event profile of the treatment. Many of the additional therapies should be given as a trial treatment under strict control, especially when efficacy has not been convincingly scientifically proven.