Victoria’s grass pollen season runs from 1 October to 31 December, bringing an increase in asthma and hay fever symptoms and the chance of ‘thunderstorm asthma’.
Thunderstorm asthma is triggered by a unique combination of high pollen levels in the air and certain thunderstorm conditions. Even people who have never had asthma before can be affected.
It can occur when pollen grains are drawn up into the clouds as thunderstorms form. The pollen grains absorb water, swell and burst open. Tiny particles containing pollen allergens are released and can be drawn into the lungs, making it difficult to breathe.
People with current, past or undiagnosed asthma, suffer seasonal hay fever or are allergic to ryegrass pollen could be at risk of an asthmatic reaction caused by thunderstorm asthma. Having both asthma and hay fever or poorly controlled asthma increases the risk even further.
Hay fever or asthma can produce symptoms similar to coronavirus such as a runny nose, cough or shortness of breath. Anyone who develops these symptoms over the season is urged to get tested for COVID-19.
For people with asthma or hay fever, especially those who experience wheezing or coughing with their hay fever, thunderstorm asthma can be sudden, serious and even life-threatening.
Melbourne experienced the world’s largest epidemic thunderstorm asthma event on 21 November 2016, which resulted in nine deaths and thousands of people presenting to Victorian public hospital emergency departments with breathing difficulties in a short period of time.
Those at increased risk should:
- avoid being outside during thunderstorms, especially in wind gusts that come before the storm.
- have an asthma reliever/preventer medication appropriately available (as discussed with your doctor or pharmacist)
- follow their asthma action plan and have practical knowledge of the four steps of .
If you have hay fever, see your pharmacist or doctor for a hay fever treatment plan and check whether you need an asthma reliever puffer – which is available from a pharmacy without a prescription.
Victoria’s thunderstorm asthma warning system is available on the and will remain in place until the end of December.
The website and app provide forecasts, information and alerts about potential thunderstorm asthma conditions using a traffic light scale of: green for low, orange for moderate, and red for high.
Pollen count expected to be high – says leading allergy expert, Prof. Jo Douglass
Professor Jo Douglass, one of Australia’s leading allergy experts from The Royal Melbourne Hospital and University of Melbourne says it is critical that anyone suffering from hay fever or asthma to start taking preventers now, with the pollen count expected to be high following a relatively wet end to winter.
“Research shows that thunderstorm asthma events happen every five to seven years, so we are owed one and it will come, so we want to keep people safe particularly as we navigate through this (COVID-19) pandemic and the best way to stay safe is to take your preventers,” Professor Douglass said.
“You can get the Melbourne Pollen app, which is linked to the emergency services, which will warn you if there is any expected thunderstorm events, and if so, my advice is to stay inside with the windows closed and be sure to keep your prevention medication nearby,” she said.
