Too many people with asthma are accepting regular breathlessness and wheezing as normal, when these are signs their condition is under-treated.
Not treating asthma appropriately leaves people vulnerable to severe attacks like those experienced in the recent Melbourne thunderstorm asthma event, said a leading respiratory physician.
Also some people with asthma aren't aware they have the condition, and this could have been an added factor in Melbourne, said Matthew Peters, professor of respiratory medicine at Macquarie University.
Asthma deaths overall in Australia have dropped dramatically in the last 25 years, but poor control of symptoms remains a problem for many people with asthma.
Research by Professor Peters and others has shown one in four people with asthma do not have their symptoms managed properly.
This is mostly because they are not using regular asthma preventer medication (or not using it properly), leaving them vulnerable to severe asthma events.
While a combination of weather and high pollen counts was thought to be the trigger in Melbourne, vulnerable people could also have bad attacks triggered by things like viruses.
Under-treating asthma may also cause lung function to get worse over time, and this may not be reversible.
Asthma occurs when people with sensitive airways respond to certain triggers in the environment, causing their airways to become narrowed, inflamed and to secrete mucus.
In Melbourne, it is thought the cause was a freak combination of rain and winds, which caused pollen to break into tiny particles that were inhaled deep into people's lungs.
Acute asthma attack
A person having an acute asthma attack (a sudden or severe flare-up of symptoms) will usually:
- Breathe quickly
- Have tightness in their chest
- Feel distressed about not getting enough air
- They may have an audible wheeze but this can disappear in a bad attack because there is little air movement.
- Often they can't speak or can speak only a few words or in short phrases.
- In extreme cases, they may turn blue from lack of oxygen.
- Treatment is to give Ventolin if you have it, and call an ambulance.
Key warning signs
Feeling breathless or wheezy, particularly at night or when trying to exercise, are key signs asthma is poorly controlled, Professor Peters said.
People tended to think 'Oh everyone with asthma has this', he said.
"But what people have come to know and accept as normal is not the best achievable in terms of reducing the risk of really bad attacks."
This means their quality of life is not as good as it could be, but also means they are vulnerable to potentially life-threatening episodes.
"They're not using enough treatment to get them better and reduce the risk of bad asthma episodes.
"Thunderstorm asthma is an extraordinary event and the deaths are tragic. But I would probably predict most of them were avoidable in some way."
'Preventer' medication vital
Many people with asthma think it is normal to use medication like Ventolin to relieve asthma daily.
"If people are having to use their Ventolin [asthma relieving medication] every day, they've definitely got a problem and they need to see their GP," Professor Peters said.
Anyone with more than occasional symptoms should be taking a preventer medication, which reduces the frequency of severe attacks and improves lung functions.
Reliever medication, commonly known as the blue puffer, should be taken only occasionally when breakthrough symptoms occur.
"A preventer is something taken once or twice daily whether you feel good, bad or indifferent. It represents the core treatment for your asthma. If you control your asthma well now, your lung function will be better long term," he said.
"You can't say 'I'm going to defer treatment for four or five years and suddenly start treatment and [expect to] get back to the same point'."
Hayfever and asthma
It has been reported that many of those affected by significant breathing problems in the Melbourne event did not have pre-existing asthma, or perhaps suffered only hayfever.
But Professor Peters believes it is likely they did in fact have asthma, just that it had not been diagnosed, probably because their symptoms and lung function had never been carefully assessed.
"Asthma is common in people with hayfever. I don't want everyone who's just got hayfever and never been breathless and has never used Ventolin to panic and rush off to their GP...
"But if they have hayfever and frequently get a cough and a little bit wheezy when they get a cold or other things, they should maybe be thinking about whether what they have goes beyond just hayfever."
It is possible to have asthma and never be diagnosed because people often don't tell their doctor about their symptoms or if they do, their doctors don't always investigate them properly, Professor Peters said. Sometimes asthma symptoms were mistakenly attributed to other conditions.
Adult asthma
It was also true that some people with asthma may have been diagnosed in the past but thought the condition had gone away.
However, it is very unusual for adults to grow out of asthma (although children can grow out of it).
Incorrect use of asthma inhalers is another common problem that can lead to inadequate symptom control. (The National Asthma Council of Australia has videos showing the correct use of inhalers.)
Everyone with asthma should have their condition reviewed every year, although research showed only half of them do, Professor Peters said.
Asthma death mystery
He said it was hard to know why some of the deaths in Melbourne occurred some days after the initial breathing difficulty was experienced. This remains to be determined by the coroner. However some possibilities included:
- So-called refractory asthma, which does not respond to treatment — although this is unusual;
- Complications of the original severe attack, such as a brain injury caused by reduced oxygen reaching the brain;
- Complications of the intensive care unit care they needed;
- Incidental events that can occur during critical illness, such as heart attack or stroke.
It was hard to know why deaths from asthma in recent decades had gone down while people's control of asthma symptoms remained poor, Professor Peters said.
"I think you probably don't need to take much asthma preventer to dramatically reduce your risk of dying from asthma. A dose here and there is enough.
"But it's not enough to suppress all your symptoms. It may still leave you vulnerable in a thunderstorm context for example."