Professor David Denning, of Manchester University and director of the National Aspergillus Centre, says: ‘Steroids often don’t control asthma very well, which means constant coughing, not sleeping and not being able to walk very far.
‘For a minority of patients, there is also a greater risk of a fatal asthma attack.’
In fact, oral steroids could make the problem worse, according to a study by another Manchester University team last year. It found severe asthmatics were ten times more likely to have higher levels of mould spores in their lungs when they were taking steroids, something researchers warned most doctors would be unaware of.
‘This is a problem for patients with low immune defences due to cancer treatment, transplant operations, chronic obstructive pulmonary disease and immune system illnesses including AIDS,’ says Prof Fisher. ‘Those with severe influenza are also at risk.’