Most Melbournians recall the horrific Thunderstorm Asthma (TA) event last year. Experts are predicting increased TA events in the future because of climate change and so everyone needs to know about TA and how to protect themselves. Read on …
What is TA?
TA is triggered by a dangerous union of weather conditions, including a fall in temperature and thunderstorm conditions, combined with a high allergen (pollen) count. These conditions don’t always lead to a TA event or epidemic.
TA events may lead to serious breathing problems, including death and may compromise local health services. Melbourne experienced the worst and most deadly epidemic of TA recorded globally in 2016. Emergency services were overwhelmed and many hospitals needed to enact their emergency plans. Nine people died.
What causes TA?
TA is thought to arise from concentrated pollen particles resulting from the movement of cold air, which forms a shallow band of air at ground level, containing high concentrations of allergens, such as pollen, fungi, plant sap, decayed plant material particles. During a thunderstorm, rain and humidity hydrate pollen particles, which can rupture. Ruptured pollen releases concentrated tiny fragments which can be breathed into the lungs and cause asthmatic reactions in susceptible people by causing swelling, extra mucous production and narrowing of the airways.
Can TA occur at any time?
Globally severe asthma epidemics during thunderstorms occur in the hay fever (pollen) season. In Australia, this period is from October to mid-December.
Could I develop breathing problems during TA?
Anyone may potentially experience asthma for the first time during a TA event. This includes people who have never been diagnosed with asthma, people with springtime hay fever (pollen exposure leads to sneezing, running or blocked nose, itchy eyes) and people with no known underlying respiratory disease. Younger adults appear to be particularly at risk of TA, possibly due to undiagnosed respiratory conditions.
Who is most at risk?
While everyone is potentially at risk, people with a history of asthma, allergies or hay fever (allergic rhinitis) are at greater risk of experiencing asthma like symptoms during a TA event. Around one in nine Australians have asthma and 80% of people with asthma also have hay fever. Over one in seven Australians have allergic rhinitis.
What are the symptoms of TA?
The symptoms of TA are the same as those observed in an acute asthma attack. Symptoms include wheezing, coughing, tightness in the chest, shortness of breath and difficulty breathing. The initial 20-30 minutes of a thunderstorm is believed to be a critical time. People with pollen allergies can inhale a high concentration of allergens at this time, leading to the development of asthma like symptoms, which can be very severe.
How can I protect myself?
Taking precautions may help prevent or minimise potential TA effects. Ideas include:
- Know the weather forecast – The Bureau of Meteorology and Melbourne Pollen Count have useful websites, smart phone apps and twitter feeds. Pollen forecasts warn when high pollen levels are expected, enabling people to take appropriate precautions during danger periods.
- Stay indoors – People with asthma or hay fever (allergic rhinitis) should try to stay indoors during thunderstorm warnings in Spring or Summer and on high pollen days. They should also remain inside during and after a thunderstorm. Keeping doors and windows closed and staying in air-conditioned environments can help reduce allergen exposure.
- People with known respiratory problems – People with asthma or hay fever should take their regular medications, adhere to their Asthma Management Plan if they have one, continue to use their regular medications and ensure regular medications (including relievers) are available in adequate amounts. In the event of an asthma attack during a TA event, people with asthma should follow their Asthma Management Plan and/or seek urgent care, if required. Only a few people with asthma taking regular preventers required admission to hospital in the recent TA event in Melbourne.
- Know when to take seek medical advice – Seek medical attention urgently if you experience asthma like symptoms such as coughing, chest tightness, wheezing or shortness of breath during a TA event. Medical advice should be sought urgently for any person whose condition worsens. Signs and symptoms of deteriorating status include obtaining little or no relief from reliever inhalers, inability to speak comfortably, and/or lips turning blue.
Lastly …
People who have previously had TA and are taking medications for asthma prevention may still be at risk of relapse of TA during a subsequent storm event. To date, one case of relapse has been reported.
Further Reading
1. Thunderstorm asthma pages on the Better Health Channel, the Asthma Australia website, the Australasian Society of Clinical immunology and Allergy (ASCIA) website
2. Pollen Count information is available on the Asthma Australia Website.
3. Newspaper article – Five-point plan on avoiding thunderstorm asthma, written by an expert in this field.
http://www.smh.com.au/national/health/fivepoint-plan-for-avoiding-thunderstorm-asthma-20161125-gsxtl1.html