Many more people than previously thought are at risk of thunderstorm asthma, particularly people who have hay fever, a survey reveals.
The survey of more than 500 staff and volunteers across Eastern Health found 41% experienced symptoms of thunderstorm asthma during the crisis in Victoria last year that killed nine people and hospitalised thousands more.
Data presented at the TSANZSRS meeting in Canberra showed about a third (32%) of the 500 respondents had a previous history of asthma and almost half of them (49%) experienced symptoms during the 2016 thunderstorm asthma event.
Importantly, of those healthcare workers with no prior history of asthma, 37% reported symptoms such as hayfever, shortness of breath, cough, chest tightness and wheeze during the storms.
The survey found people with a history of allergy to plant and mould allergens were more likely to experience symptoms during the thunderstorms than people with other allergies such as to dust mites and cats.
Whether people were inside or outside during the thunderstorms did not influence the development of symptoms.
Co-researcher Professor Francis Thien, director of respiratory medicine at Eastern Health, said the people most seriously affected were those with no history of asthma who therefore had no medication to hand.
However he said at least half of those people when questioned had symptoms suggestive of undiagnosed asthma.
“Certainly a lot of people were caught out, not prepared with access to bronchodilators and significantly affected by asthma and other respiratory symptoms,” he told the limbic.
He said a reasonable precaution, even for those people with only a history of hayfever, was to consider purchasing a puffer over-the-counter to have on hand during the pollen season.
However there is a seasonal increase in respiratory exacerbations every November, Professor Bruce Thompson, head of physiology services at the Alfred Hospital told the limbic.
“The issue is allergic rhinitis has a similar mechanistic action to asthma and these people, under certain environmental conditions, are primed to have a significant asthma event,” he said.
“There is the potential to pre-empt this with a significant public and professional education program.”
Professor Thompson said small-particle inhaled corticosteroids may have increased efficacy in controlling asthma driven by inflammation in the small airways given the particle size of the medications was similar to the allergens in thunderstorm asthma.
While pollen particles were typically >20um in size, he said the unique environmental feature of the thunderstorms was that smaller starch molecules of 2.5um were released from the pollen.
TSANZ President Professor Peter Gibson said the findings that many more people than previously thought were at risk of sudden, unforeseen asthma attacks was a wake up call ahead of the next pollen season.
“It is essential that we invest more research into this phenomenon and educate our health services and public to take preventative and preparedness measures,” he said.