Over the last 20 yrs, extensive investigation of the pathogenetic mechanisms of asthma has led to a better understanding of the disease and to a more cognitive approach to its therapies. Controlled studies show that most asthmatic patients can achieve asthma control and lead normal lives with moderate doses of medication 1, 2, but surveys show that a substantial number of patients still face symptoms and limitations, probably due to inadequate management 3. This is a matter of concern for both the medical community and health authorities, as control of asthma can and should be achieved in the majority of patients. Nevertheless, there still remain some asthmatics who have persistent symptoms and frequent exacerbations despite specialist care and continuous, intensive, high-dose treatment 4–6. These severe and difficult-to-treat asthma patients have impaired health status and account for over half of the cost of the disease and probably all of its mortality 7. Risk factors and mechanisms involved in this situation are not clear, and the clinical presentation is not homogeneous. Recent series have shown that severe and uncontrolled asthma may be associated with psychopathology, nonadherence to therapy, poor socioeconomic status, continuous exposure to inducing factors, severe upper airways disease, gastro-oesophageal reflux and viral or Chlamydia pneumoniae infection 4–6, 8–10. Several patterns may be observed, including sudden-onset fatal and near-fatal, brittle, aspirin-induced, steroid-dependent/steroid-resistant, severe occupational and pre-menstrual asthma. These clinical symptoms and characteristics can probably be attributed tothree underlying mechanisms: 1) airways inflammation; 2) bronchial hyper-responsiveness (BHR), which may or may not be associated with inflammation and/or bronchial smooth muscle hyper-reactivity 11; and 3) fixed airways obstruction.
In this issue of the European Respiratory Journal, Bumbacea et al. 12 present their findings from a study examining clinical characteristics …