Work-related asthma affects a staggering one in four adults with asthma and yet is under-recognised and under-reported in Australia.
In response, the National Asthma Council Australia released a summary paper on work-related asthma to assist primary care health professionals better manage this preventable occupational lung disease.
Dr Ian Almond, general practitioner and member of the Australian Asthma Handbook guidelines Committee, said exposure to airborne contaminants or adverse conditions at work is an important and preventable cause of asthma and asthma symptoms in adults.
“Failure to prevent further exposure to a sensitiser or irritant in a patient with established occupational asthma could lead to rapid, irreversible deterioration in lung function,” he says.
The National Asthma Council Australia summary paper outlines some important differences in work-related asthma.
“If patients are presenting with new-onset asthma or a recurrence of previous asthma, primary care health professionals should consider the possibility of “occupational asthma” that is caused by airborne substances (sensitisers or irritants) in the workplace.
“More than 300 workplace agents* have been reported to cause sensitiser-induced occupational asthma, which accounts for about 90% of occupational asthma,” says Dr Almond.
Immunoglobin E (IgE)-mediated allergic reactions are induced by high-molecular weight allergens, such as plant allergens, animal allergens, fungi and enzymes.
This might affect people who are farmers, bakers, textile industry workers, gardeners, process workers or food processors and their asthma is often preceded by symptoms of allergic rhinitis.
Occupational asthma can also be caused by low-molecular weight sensitisers including chemicals, dusts or fumes, which mostly cause asthma in patients who are spray painters, adhesive workers, metal platers, electronic industry workers and carpenters.
Dr Almond said the summary paper also outlined examples of “work-exacerbated asthma”, when a patient’s pre-existing asthma may be worsened by workplace conditions.
“About one in five adults with asthma experiences worsening of asthma at work, ranging from increased frequency of symptoms and need for reliever medication to acute flare-ups requiring emergency care.
“Workplace triggers can include respiratory irritants (dusts, fumes, sprays, gas, aerosols, liquids), aeroallergens (dust mite, pollens, animal dander), very hot or very cold air, physical exertion, or emotional stress,” he says.
With an estimated 1000 to 3000 new cases of asthma caused by work per year, links between asthma and exposures in the workplace should be considered in all people of working age with asthma, particularly if their asthma develops during their adult life or has been difficult to control.
“All occurrences of work-related asthma are potentially preventable and the summary paper gives primary care health professionals the latest tools to help them screen patients and decide whether referral to a respiratory physician or clinic with experience in work-related asthma is required,” says Dr Almond.
A 2020 joint position statement released by National Asthma Council of Australia and the Thoracic Society of Australia and New Zealand can be found at: onlinelibrary.wiley.com/doi/10.1111/resp.13951
Link to National Asthma Council Australia work-related asthma summary paper: nationalasthma.org.au/living-with-asthma/resources/health-professionals/information-paper/hp-work-related-asthma
* The Australian Asthma Handbook provides a list of common sensitising agents and occupations associated with exposure – asthmahandbook.org.au