Ryegrass pollen season is well underway in Victoria, this pollen is a major trigger for asthma and allergic rhinitis (hay fever) and high levels of pollen contributed to the state’s Thunderstorm Asthma
(TSA) Epidemic in 2016.
Asthma Australia is urging people with not just asthma, but also hay fever, to be prepared.
On 21 November 2016, more than 3500 people across Victoria presented to emergency rooms in respiratory distress.
Tragically, the 2016 TSA event was associated with 10 asthma fatalities.
Ryegrass pollen had peaked in the days leading up to the event. Rain and moisture ruptured the ryegrass pollen grains so they were small enough to be inhaled. A thunderstorm then brought the
particles down to ground level.
Of all those presenting with thunderstorm asthma, hay fever was present in the vast majority ( 87 per cent), while asthma was previously known to be present in only 28 per cent.
While all asthma fatalities were exclusively linked to people with an asthma diagnosis, an unusually high number of people presented to hospital with respiratory distress who had only ever had hay
fever.
Professor Jo Douglass, AO, is an Asthma Australia spokesperson, respiratory and allergy specialist and Director of Research at the Royal Melbourne Hospital. She said that the TSA event revealed that
many people who believe they only experience hay fever actually have asthma.
“We reviewed those who had presented to hospital with thunderstorm asthma. Evidence revealed that one third of people who described only having hay fever symptoms before going to hospital
with thunderstorm asthma, actually experienced asthma symptoms but did not recognise them,” MsDouglass said.
“It’s important to recognise hay fever symptoms associated with asthma, like night waking and morning wheezing, and to see a doctor for an asthma review. People with undiagnosed asthma need
to receive a formal diagnosis so they can begin to manage their condition.”
“This could help reduce their risk of an asthma attack or hospitalisation during future thunderstorm asthma events.”
It may also reduce symptoms during the spring hay-fever season such as night waking with cough or wheeze or shortness of breath when outdoors.
The general ryegrass pollen season runs from August to December in Victoria. The state has experienced a number of less serious thunderstorm asthma epidemics before the 2016 event, with
each event occurring in November and every springtime season brings an increase in emergency department attendances of those with allergies and asthma.
While TSA has been mostly described in the South-East of Australia, ryegrass pollen seasons do happen across the rest of Australia, so it’s important for all people with asthma and hay fever to be
prepared.
Susceptibility factors for thunderstorm asthma include asthma, hay fever, ryegrass pollen sensitisation (allergy), and poor use of prescribed corticosteriod-based asthma preventer therapy,
which is the mainstay of asthma management.
Being outdoors at the time of the TSA event was also identified as a risk factor.
To lower their chance of having thunderstorm asthma, people with asthma should engage in good asthma management year-round. This means ensuring they have at least an annual asthma review
with their GP and that their Asthma Action Plan is up-to-date so they understand what steps to take in the event of an asthma flare-up or emergency. Now is the perfect time for this in the lead up to
TSA season.
Using a preventer inhaler, keeping hay fever under control, taking any necessary hay fever medicines and having scripts and supply of asthma and hay fever medicines ready are also key.
Checking pollen levels, and where possible, avoiding being outside on these days, especially at the start of a thunderstorm, may also be important. We now have a world leading forecasting system
available for all Victorians to use either via the VicEmergency app or the website.
Ryegrass pollen seasons across Australia
Vic: August to February
NSW: September to November
ACT: October to Februrary
Tas: October to December
SA: October to March
WA: October to November
QLD: September to Novemebr
