Pollen season warning about ‘thunderstorm asthma’

Doctors are calling for extra warnings about the increased risk of asthma episodes when thunderstorms erupt in spring and summer after there has been a lot of pollen around, as evident in recent epidemics of ‘thunderstorm asthma’ in Melbourne.

In a letter to the Medical Journal of Australia on 7 November, Dr Megan Howden of the Department of Respiratory and Sleep Medicine at Austin Health in Melbourne said additional warnings were needed during thunderstorm seasons for people who are sensitive to pollen.

Patients with asthma should have an asthma management plan, and pollen-allergic patients should be told to seek medical help quickly if they experience symptoms of asthma, she wrote.

“We propose that additional warnings of elevated risk of asthma exacerbations in pollen-allergic individuals should be made when springtime and summertime thunderstorms follow several days of high or extreme pollen counts,” Dr Howden said in her letter.

“Individuals with seasonal asthma should use preventer medication, at least during spring, and should have an asthma management plan.

“Patients with allergic rhinitis should be warned of the possibility of new-onset thunderstorm asthma and advised to seek assistance rapidly if asthma symptoms manifest.”

Dr Howden said the onset of spring, together with high winter rainfall in Melbourne and surrounds, heralded another severe pollen season and raised the risk of allergic rhinitis and asthma in people who are sensitive to pollen.

Dr Howden described thunderstorm asthma as a phenomenon of a sudden increase in acute asthma exacerbations temporally related to a thunderstorm. Epidemics of thunderstorm asthma were evident in 1987, 1989 and 2010, when there were up to ten-fold increases in asthma presentations to emergency departments across Melbourne.

It’s believed that rye-grass pollen is the major cause of the thunderstorm epidemics, with the moisture in the air during developing thunderstorms causing the pollen to rupture and the outflow winds of the storms causing the ruptured pollen particles to concentrate at ground level.

(Source: Australian Medical Association (AMA): Medical Journal of Australia)

More information

For more information on spring allergies, including why people get allergies, how allergies affect you and how to prevent them, as well as some useful animations and videos, see Spring Allergies.