Key Points
Î Severe asthma is defined as asthma that requires treatment with high
dose inhaled corticosteroids plus a second controller and/or systemic
corticosteroids to prevent it from becoming ''uncontrolled'' or that
remains ''uncontrolled'' despite this therapy. (See Tables 1 & 2)
Î Severe asthma is a heterogeneous condition consisting of phenotypes
such as severe allergic asthma, eosinophilic asthma, neutrophilic
asthma, chronic airflow obstruction, recurrent exacerbations and
corticosteroid insensitivity.
Î The prevalence of severe asthma in adults and children is estimated to
be 5–10% of the total asthma population.
Î The ATS/ERS Severe Asthma guidelines make recommendations
addressing the roles of computed tomography, sputum eosinophils,
and exhaled nitric oxide in the diagnosis of severe asthma.
(see Table 3)
Î The ATS/ERS Severe Asthma guidelines make recommendations
addressing the roles of anti-IgE antibody, methotrexate, macrolide
antibiotics, anti-fungal agents, and bronchial thermoplasty in the
treatment of severe asthma. (see Table 6)