Asthma affects 11 per cent of the Australian population, and whilst the public generally considers it a familiar condition, experts are warning that we must not underestimate the importance of having the diagnosis confirmed.
In an article published by The Medical Journal of Australia, Professor Helen Reddel, respiratory physician at Royal Prince Alfred Hospital and research leader in the Clinical Management Group at the Woolcock Institute of Medical Research, Sydney, lays out the importance of ensuring general practitioners (GPs) thoroughly assess their patients for asthma, as well as distinguishing between the symptoms of asthma and other similarly presenting conditions.
This is extremely important as many of the common symptoms of asthma may actually be due to a variety of acute and chronic health conditions, with the main contenders being:
- Inducible laryngeal obstruction (ILO)
- Chronic obstructive pulmonary disease (COPD)
- Cardiac failure
- Hyperventilation or panic attacks
Within Reddel’s article, she provides a detailed table listing the key details of each condition, providing a nuanced guidebook for GPs.
To complement her article, Reddel has also provided some clinical vignettes, two case-studies to illustrate examples of how asthma-related differential diagnosis is carried out, which are available via this link.
Reddel tells Aged Care News that this topic is of importance to the aged care industry, as older persons may not have had the diagnosis of asthma confirmed in their earlier years. This was sometimes due to the stigma that used to be attached to the condition.
“We’ve gone from a situation about 30 years ago where people would do anything to conceal that they had asthma… we did some interviews with patients 20 years ago and some of the older patients said that their mother told them to not let on that they had asthma, otherwise they’d never get married.
“In the past, people also had difficulty getting life insurance if they had asthma.
“So, we’ve gone from stigma to acceptance of asthma — accepted as being so common that ‘everyone has it’ — and that’s really good, but it has come with a degree of complacency, especially around diagnosis.”
Whilst reducing stigma is good news for encouraging people to come forward and discuss their respiratory health with their GP, instantly defaulting to a diagnosis of asthma, without diligently ruling out the alternatives, may set the scene for the insidious progression of another undiagnosed, chronic illness.
“If someone hasn’t actually had a diagnosis confirmed by the time they get to residential aged care, then the [inappropriate] treatment would just then be continued,” Reddel notes.
“It is really important that if someone’s having problems with respiratory symptoms such as cough, wheeze, shortness of breath or chest tightness, that they actually seek help about it rather than just doing more of the same.”
More considerations for older Australians
All of the four mimic conditions mentioned by Reddel are common in all ages, with cardiac failure more common in older Australians.
“In people over 65, about 10 per cent of people have cardiac failure, so it’s about as common as asthma.”
Furthermore, COPD is a disease that tends to emerge in older age in people who used to be smokers, but time of initial diagnosis may be delayed as patients put their increased breathing difficulties down to asthma.
“Older people are more likely to have been smokers in their younger age… those people are at more risk of having COPD than younger people.”
In older women, hormonal changes due to menopause may be associated with a reduction in lung function, as compared to men.
“There’s been quite a lot of studies that have looked long term at lung function in men and women and in women, you see a change in lung function after the menopause that’s not been fully explained,” Reddel says.
Over-the-counter solutions could backfire
With the normalising of asthma has come an increased reliance on ‘quick-fix’ inhalers such as salbutamol — including brand names such as Ventolin — which in Australia can be acquired over the counter at your local pharmacy.
But reliance on such a medicine, without prior consultation with a GP or respiratory physician, could have a number of undesirable side effects in the long run.
“In people who have asthma, their airways (breathing tubes) are inflamed and what we call ‘twitchy’,” Reddel explains.
“There’s a muscle around the airways… and that muscle, in people with asthma, contracts more easily and to a greater extent than in people who don’t have asthma.
“When you give a medication like Ventolin, it makes that muscle relax and allows the airways to open up again, but only for about four hours.
“It doesn’t treat the inflammation in the airways that causes the airway muscle to contract, and it doesn’t prevent asthma attacks from occurring. Instead, to treat that inflammation, to control symptoms, and to reduce the chance of having asthma attacks, you need an asthma preventer inhaler.
In fact, the more you take of medications like Ventolin, the less well the airways react to it and the greater the twitchiness of the airways.
“So when people are overusing Ventolin, it makes their asthma worse.”
Another reason for asking for the diagnosis of asthma to be confirmed is to make sure that you are taking the right treatment.
Asthma assessments are most accurate when done before a long-term preventer treatment is initiated because, as Reddel explains, assessing ‘variability of lung function’ is a vital indicator of asthma.
“To confirm the diagnosis of asthma, we need to document excess variability of lung function, so we might measure the person’s lung function before and after giving them some Ventolin, for example — that’s one of the most common tests that is used.
“If you want to capture that evidence that this person really does have asthma, you should do it when they first present because you’ve got your best chance then of finding that characteristic variability.”
However, when assessing and treating older adults, it’s important to remember that their airways may be less responsive.
“So instead of getting that brisk response when they take Ventolin, they may find that their lung function doesn’t improve as much as when they were younger.
“That’s partly due to changes in the airways. As we get older, there’s what we call ‘remodelling’ of the walls of the airways and the structure of the lungs.
“That means that over time, you can develop what we call ‘persistent airflow limitation’. This does not necessarily rule out an asthma diagnosis, but it is another reason why it’s important to get the diagnosis confirmed when you first have breathing problems.
Ask for a referral if symptoms don’t respond to treatment
Reddel notes that for most people with asthma, their symptoms can be well-controlled and asthma attacks prevented with a low dose asthma preventer, plus a written asthma action plan, with a small proportion of people needing higher doses of a preventer inhaler.
However, if the person’s respiratory symptoms are actually due to a condition other than asthma and further testing isn’t done, the doctor may keep increasing the dosage of asthma medicines, to no avail.
“This exposes the person to the risk of treatment side effects … but the more important risk is that you may be missing some other condition that actually needs specific treatment.”
“In addition, for a small proportion of people with asthma, probably 5 per cent, their asthma is relatively unresponsive to normal preventer treatments, and their asthma may still not be controlled despite taking high dose preventer treatment, and they’re still having attacks.
“For those people, there are some important new treatments available through the PBS that are targeting the underlying mechanisms of severe asthma, and they can be life changing.”
Ultimately, for patients whose respiratory symptoms have not responded to treatment for asthma, Reddel encourages GPs to consider referring them for consultation with respiratory specialists, who have the expertise and resources to determine exactly which condition is causing their respiratory issues.
“I have huge respect for GPs who have to manage around 350 conditions, often in 10 minutes.
“But you don’t expect them to necessarily have access to all of the testing that you might have in specialist care.
“Because several other conditions can mimic asthma— and because uncontrolled asthma is burdensome for the patient and for the health system —encouraging a request for referral if things are not going well is a good message to have.”
A little about Professor Helen Reddel
Professor Helen Reddel MBBS PhD FRACP is a respiratory physician working to improve treatment for asthma and COPD.
She is a Research Leader in the Clinical Management Group at the Woolcock Institute of Medical Research, Chair of the Science Committee of the Global Initiative for Asthma (GINA), Director of the Australian Centre for Airways Monitoring, and a member of the Australian Asthma Handbook Guidelines Committee.