March 5, 2024 -- Thunderstorm asthma can strike with little warning, leaving people with the symptoms of an asthma attack during or after the dark clouds pass.
If you’re unfamiliar, the risk for a thunderstorm asthma attack grows when heavy storms arrive on a day with very high pollen or spores. The storm uplifts these particles, adds water, and causes them to explode into smaller grains. The electrical activity in a storm can do the same. Next, strong winds sweep these particles down and across the ground. People in the path of the storm can experience shortness of breath, coughing, and wheezing.
If thunderstorms are predicted to become more frequent and more severe with climate change, will the same hold true for thunderstorm asthma?
“Yes, if only because the amount of pollen appears to be increasing in many areas due to climate change,” said Frank S. Virant, MD, chief of the Allergy Division at Seattle Children’s Hospital.
Most cases of thunderstorm asthma occur in the spring and early summer, but that also could change. Pollen seasons “have been getting longer and more intense,” said Shaan M. Waqar, MD, an allergist at ENT and Allergy Associates in Plainview, NY.
“Thunderstorm asthma events are rare, but our changing environment and the increase in the number of people with allergies may make such events more common and more severe into the future,” agreed Paul J. Beggs, PhD, associate professor in the School of Natural Sciences at Macquarie University in Sydney, Australia.
How to Minimize Your Risk
If you’re sensitive to pollen, continue to monitor outdoor levels, particularly during tree, grass, and weed pollen season, Virant recommended. Also pay attention to weather reports. Watch for thunderstorms that could “amplify exposure to the pollen with 40-plus mile per hour winds and often colder air downdrafts.” Cold is an additional asthma trigger, he noted.
People with asthma should try to stay indoors with windows and doors closed during strong thunderstorms and for several hours afterwards. Using air filters can also help reduce risk, said Deepti V. Manian, MD, an allergist and immunologist at Stormont Vail Health in Topeka, KS.
Continue controller therapies -- such as longer-acting inhalers and allergy medications -- and use a rescue inhaler or nebulizer for prompt treatment of symptoms, recommended Donald J. Dvorin, MD, of The Allergy and Asthma Doctors in Mount Laurel, NJ. Ideally, people seeking shelter indoors during storms should be “accompanied by friends or family who can help them transport quickly to a hospital if needed.”
Asthma Diagnosis Not Required
Even people who would not consider themselves to have asthma can be seriously affected. For example, people with hay fever, or allergic rhinitis as it’s also known, are also at risk, said Ajay Kevat, MBBS, MPH, of the respiratory department at Queensland Children’s Hospital in Brisbane, Australia.
People with hay fever can also experience stronger symptoms during and after thunderstorms. Optimally treating allergic rhinitis during the pollen season with non-sedation antihistamines and nasal steroids can help, Virant said, instead of “chasing symptoms with medication after they are already severe.”
Part of the challenge is connecting severe weather to worse asthma symptoms. “In my experience, there is a lack of awareness surrounding thunderstorm asthma,” Manian said. For example, people with non-allergic rhinitis, also known as vasomotor rhinitis, can also experience the effects. “It often surprises many of my patients when I introduce the concept of vasomotor rhinitis, which can be triggered by environmental fluctuations.”
Gathering Clouds, Gathering Evidence
Climate change could also change which Americans experience the most storms. Researchers in a June 2022 study predicted fewer storms in the Southern plains and more storms in the Midwest and the Southeastern United States in the future.
Dvorin practices in Southern New Jersey, and in this area, "we fortunate in this area not to experience thunderstorm-induced asthma exacerbations," he said.
But climate change means that in the future, thunderstorm asthma could strike in places it has never been seen before, said Kevat, who wrote a thunderstorm asthma review article published online June 2020 in the Journal of Asthma and Allergy.
And this is not just a concern in the United States. Major thunderstorm asthma events have been reported in Italy, the United Kingdom, the Middle East, Asia, and Australia. In November 2016, for instance, a strong set of storms swept across Melbourne, Australia. Temperatures dropped 10C (about 18F), humidity rose above 70%, and particulate matter like pollen became more concentrated in the air.
This event spurred a “thunderstorm asthma epidemic of unprecedented magnitude, tempo, and geographical range and severity,” Beggs and colleagues wrote in their June 2018 report in The Lancet Planetary Health.
Large-scale events like this can affect entire communities and quickly overwhelm local health care resources. Within 30 hours of the Melbourne storms, 3,365 people more than usual came to local emergency departments with respiratory issues -- and 476 with asthma were admitted to the hospital. Ten people died: five in the hospital and five who could not be resuscitated or died while waiting for emergency services.
More research is needed “so as to best prepare for this unpredictable, significant public health threat,” Kevat wrote.
People whose asthma is triggered by pollen or mold spores are particularly at risk for thunderstorm asthma, Waqar said. If you’re unsure, an allergist can help diagnose and treat your allergic risks.
More severe thunderstorms are just one asthma trigger associated with climate change. Last summer, Canadian wildfires sent smoke across the northern U.S. and triggered widespread asthma exacerbations. See the WebMD slideshow to learn more about how rain, humidity, and seasonal weather changes can also present asthma challenges.