Sorry all - stupid jargon . . .
Basically the same things that result in asthma exacerbations (i.e. that cause worse asthma symptoms) are the things found to increase so dramatically in the bird flu virus.
When people with asthma are exposed to certain “triggers” - molds, dust, pollen, cats, cigarette smoke, etc. they may experience a sudden worsening of symptoms. This is because “inflammatory mediators” - i.e. chemicals which are supposed to protect us from disease - increase pathologically. This causes the airways to become smaller and for mucus secretion which causes the airflow to slow considerably. This is asthma in a nutshell.
With the bird-flu virus, many of these inflammatory mediators are increased dramatically as well. This may result in severe respiratory symptoms as the airways narrow causing difficulty in breathing.
This is why i considered that steroids might be useful here as - yes Mary - they are immune suppressants.
I hope that this clears up the fog, and again my apologies.