Epidemic thunderstorm asthma

Epidemic thunderstorm asthma happens when a large number of people develop asthma symptoms over a short period of time, triggered by high amounts of grass pollen combined with a certain type of thunderstorm.

What is epidemic thunderstorm asthma?#

These events are thought to be triggered by a unique combination of high grass pollen levels and a particular type of thunderstorm. The world’s largest recorded epidemic thunderstorm asthma event saw thousands of people develop breathing difficulties in a very short period of time.

Grass pollen grains are swept up by the wind and carried long distances. Some burst open and release tiny particles that become concentrated in the gusts of wind that arrive just before a thunderstorm. These particles are small enough to be breathed deep into the lungs, where they can rapidly trigger asthma symptoms and make it difficult to breathe.

This can become very severe, very quickly, and many people may need medical help at the same time. People who experience wheezing or coughing with their hay fever are especially affected. That is why it is important for people with asthma or hay fever to understand thunderstorm asthma and how to help protect themselves during grass pollen season.

When do these events happen?#

Epidemic thunderstorm asthma events are uncommon and do not occur every year. In some regions they can happen during the local grass pollen season.

Who is at risk?#

Those at increased risk of thunderstorm asthma include:

• people with diagnosed asthma
• people with undiagnosed asthma (those who have asthma symptoms but have not yet been diagnosed)
• people with hay fever, especially if they are allergic to grass pollen

Having both asthma and hay fever, or having poorly controlled asthma, increases the risk further. Thunderstorm asthma can affect people living in city, regional or rural areas, even if they have no history of asthma. Remember that a wide range of triggers can set off a person’s asthma symptoms.

Recognising asthma symptoms#

Asthma can start at any age, even in adulthood. It is important to recognise the symptoms and see your doctor if you experience any of them. Common asthma symptoms include:

• a persistent cough
• wheezing (a high-pitched sound from the chest while breathing)
• breathlessness
• a feeling of tightness in the chest

These symptoms mean a person’s lungs (lower airways) are affected. Asthma symptoms come and go over time, and you do not need to have all of them to be diagnosed with asthma. Not everyone experiences the same symptoms.

Sometimes people with asthma do not notice their symptoms, and sometimes they do not manage them by seeing their doctor or using their medication. People with well-controlled asthma have mild symptoms, less often.

A diagnosis of asthma is more likely if you have eczema or hay fever, or close relatives with allergies, and if your symptoms:

• improve quickly with reliever medication
• keep coming back, or happen at the same time each year
• are worse at night or in the early morning
• are clearly triggered by exercise, allergies or infections

Recognising hay fever symptoms#

Around one in four people with hay fever also have asthma, and pollen can trigger both asthma and hay fever symptoms. Common hay fever symptoms include:

• itchy, watery eyes
• a runny nose
• an itchy nose
• sneezing

These symptoms mean a person’s eyes and upper airways are affected. Hay fever does not include wheezing, shortness of breath or chest tightness, which may be asthma symptoms instead. If you have hay fever and have also experienced wheezing, shortness of breath or chest tightness, see your doctor.

How to protect yourself during grass pollen season#

Everyone in the community should know the signs and symptoms of asthma and know asthma first aid, so they know what to do if someone is having an asthma attack. Anyone at increased risk should:

• learn about thunderstorm asthma and how to help protect themselves during grass pollen season
• where possible, avoid being outside during thunderstorms in grass pollen season, especially in the wind gusts that come before the storm
• go inside and close doors and windows; if an air conditioner that brings outside air in is running, switch it to recirculate
• have reliever medication available during grass pollen season and know how to use it (ideally with a spacer)
• be alert to asthma symptoms and act on them, following an asthma action plan if you have one, or asthma first aid if you do not

Always carry your reliever medication with you, as this is your emergency asthma first aid medication. Reliever puffers are available from pharmacies without a prescription.

If you currently have asthma, have regular reviews with your doctor to make sure you have the right medication and good control. Make sure you have an asthma action plan and that it includes advice for thunderstorm asthma. Talk with your doctor about your risk and whether you need preventer medication over the grass pollen season.

If you have hay fever, understand that you are at increased risk of asthma, including during an epidemic thunderstorm asthma event. If you have experienced symptoms such as wheezing, shortness of breath or coughing with your hay fever, talk to your doctor. If you have hay fever only, see your doctor or pharmacist about a hay fever treatment plan and what you can do to help protect yourself, which may include having an asthma reliever puffer available.

Where forecasts are available in your area, check the epidemic thunderstorm asthma risk forecast during the local grass pollen season, and stay informed about pollen counts.

Key points#

• People who have asthma symptoms but have not yet been diagnosed are still at increased risk of thunderstorm asthma.
• Having both asthma and hay fever, or poorly controlled asthma, increases the risk further.
• A wide range of triggers can set off a person’s asthma symptoms.
• It is important to recognise asthma symptoms and see your doctor if you experience any of them.

Where to get help#