The idea of what asthma is and how it should be treated could be due for a rethink, if the findings of a new research study are to be believed.

Conventional medicine maintains that the airways become inflamed in severe bouts of asthma, and can be treated with high doses of steroids. This view is so well accepted that doctors specifically look for this characteristic inflammation when diagnosing asthma.

But research from a study team at the National Jewish Centre for Immunology and Respiratory Medicine in Denver has found that inflammation may not always accompany an asthma attack. And if there is any inflammation, it will not always respond to steroids.

The team, led by Sally Wenzel, made the discovery after studying 14 patients with severe asthma who were treated with high doses of oral glucocorticoid. Not only did they not respond to steroids, their bodies also had an abnormal number of the cells known as neutrophils.

Homer Boushey from the Asthma Clinical Research Centre at the University of California said the research should alert doctors to look for other treatments if severe asthma persists after a course of high dose steroids.

The asthma, he says, could be caused by the activity of neutrophil cells. So "effective therapy may require treatment other than the administration of yet higher doses of glucocorticoids". He hopes that further research could quickly follow on from these initial findings, which have shown the limitations of the current medical model for asthma (JAMA, 1998; 279: 883).