A common international approach is favored to define severe asthma, uncontrolled asthma, and when the 2 coincide.
Severe asthma - differential diagnosis and management (click to enlarge the image).
Uncontrolled asthma can result in:
- risk of frequent severe exacerbations (or death)
- adverse reactions to medications
- chronic morbidity (including impaired lung function or reduced lung growth in children)
Severe asthma includes 3 groups:
(1) untreated severe asthma
(2) difficult-to-treat severe asthma
(3) treatment-resistant severe asthma
The last group includes asthma for which control is not achieved despite the highest level of recommended treatment and asthma for which control can be maintained only with the highest level of recommended treatment.
Uniform definition of asthma severity, control, and exacerbations: Document presented for the World Health Organization Consultation on Severe Asthma. J Allergy Clin Immunol. 2010 Oct 4. [Epub ahead of print]
An approach to recalcitrant, severe asthma - AAAAI Ask the Expert, 2011.