Monash researchers urge more action on thunderstorm asthma

There is a confluence of meteorological and seasonal factors
in thunderstorm asthma. Harm can be minimized with alerts
and planning. Image: Better Health Channel

by Anne Crawford

Monash University researchers say there is an urgent need to highlight the physiological mechanisms underlying thunderstorm-related asthma to mitigate against an event such as last year’s catastrophic epidemic in Melbourne occurring again.

The freak asthma thunderstorm on 21 November 2016 left nine Victorians dead, caused more than 9,900 patients to present to hospitals, and overwhelmed ambulance and emergency services. It was the most lethal of its kind on record.


The researchers, from Monash and The Alfred Hospital, made their appeal in an editorial entitled ‘The Melbourne thunderstorm asthma event: can we avert another strike?’ published this month in the ‘Internal Medicine Journal’.

The article reviewed the factors behind the 2016 event, detailing the conditions that converged to cause it: high pollen counts in spring; increased moisture from an impending thunderstorm that caused pollen grains to rupture releasing tiny pollen particles: and, storm outflow winds that bring the tiny particles down to where they can be inhaled. It recommends more vigilance about respiratory conditions and increased preventive approaches.

Said first author Associate Professor Mark Hew, Head of Allergy, Asthma and Clinical Immunology at The Alfred, “Our main concerns are that thunderstorm asthma exposed our inadequacies in managing firstly, asthma, and secondly, allergic rhinitis.

“It’s the conjunction of the two that brings on thunderstorm asthma,” Associate Professor Hew said. “We’ve known for more than 20 years that patients who experience thunderstorm-related asthma in Melbourne suffer seasonal allergic rhinitis and are sensitised to rye grass pollen. Everyone in Victoria needs to know that if they have allergic rhinitis (springtime hay fever), then they are at potential risk for thunderstorm asthma,” he said.

“The event has highlighted the fact that treating allergic rhinitis is not just something optional for lifestyle reasons, but is also extremely important for patient safety. Treatments for this need to be in the forefront of GPs’, and also pharmacists’ minds,” he said.

People with known asthma should be meticulous about taking their preventers (inhaled medicine) regularly, and need to have asthma action plans to know what to do in an emergency.

The editorial reports that 36 to 44% of people who present at emergency departments with thunderstorm asthma may never have previously suffered asthma, and warns that current asthma guidelines do not cater for this group of ‘latent asthmatics’.

“The lesson for clinicians that has come out from this is that asthma is significantly under-diagnosed in the community, so we need to be more vigilant in detecting and case-finding asthma, especially in people with allergic rhinitis.”

The authors conclude that just as the catastrophic Black Saturday bushfires have changed community attitudes and preparedness, so too should the thunderstorm disaster of 2016.

“We think that with interventions at multiple levels in the community, among physicians and at government system levels, the answer should be ‘yes, we can avert another strike’. The answer has to be ‘yes’,” Associate Professor Hew said.

The four authors – Associate Professor Hew, Professor Robyn O’Hehir, Dr Michael Sutherland and Professor Francis Thien – have helped advise the State Government as part of its Epidemic Thunderstorm Asthma Clinical Guidance Reference Group.

“We are all pleased that clinicians are being able to provide input to government initiatives that are being planned, and that the Government is taking every important and appropriate step within their power, to ensure the community is protected as far as possible against future events.”

The State Government last month announced that $15.56 million would be spent on measures including research, increased monitoring and interpretation of pollen data, and a new emergency warning system.

Reference

• Mark Hew, Michael Sutherland, Francis Thien and Robyn O’Hehir. ‘The Melbourne thunderstorm asthma event: can we avert another strike?’ Internal Medicine Journal 47 (2017) doi:10.1111/imj.13408
• See also our previous feature on thunderstorm asthma