Spring Thunderstorms Bring Asthma Attacks

Bad weather plus high pollen counts make for the perfect storm

man in storm

In Melbourne, Australia, on November 21, 2016, there was the perfect thunderstorm. Wind, heavy rain, and high pollen counts put more than 8,500 people in the hospital with severe asthma attacks. Nine people died.

Many of these people who experienced almost deadly attacks had no history of asthma and previously experienced only hay fever. What exactly happened?

Asthma Explained

Asthma affects about 300 million people around the world. The number of people with asthma is increasing, a trend that has been linked to widespread urbanization. A global increase in the number of people with asthma as well as higher associated costs of the disease have led to more research examining its mechanisms and treatment.

According to the CDC, about one in 12 Americans (25 million people) have asthma. In 2008, about 50 percent of Americans with asthma had asthma attacks—many of which could have been prevented.  Moreover, in 2007, asthma ended up costing Americans $56 billion in medical costs, lost wages, and lost school days.

People with asthma most commonly present with symptoms during early childhood. About twice as many boys have asthma. By adulthood, however, asthma is equally prevalent among men and women.

Symptoms of asthma include wheezing, breathlessness, coughing, and chest tightness.

Asthma is a complex syndrome marked by the following: 

  • intermittent airflow obstruction
  • a special type of inflammation of the airways
  • bronchospasm, or spasm of the smooth muscle in the walls of the small branches of the airway, which leads to temporary narrowing.

A major risk factor for the development of asthma is atopy. Atopy is a genetic tendency to develop allergic diseases including not only asthma but also allergic rhinitis and atopic dermatitis. Of note, allergic rhinitis is also known as hay fever and atopic dermatitis is eczema. People with atopy experience heightened immune responses to common allergens found in the environment, such as pollen, mold, and certain foods.

Certain triggers can lead to airway inflammation and an asthma attack. These triggers include the following:

  • allergens (e.g., pollen)
  • viral infections (e.g., rhinovirus)
  • exercise
  • cold air
  • laughter
  • weather changes
  • medications (e.g., β-blockers)
  • occupational exposure
  • GERD
  • diet

A physician can diagnose asthma based on medical history, physical examination findings, and spirometry. Spirometry is a diagnostic test done in the office, which measures the amount of air that you inhale, the amount of air that you exhale, and the time it takes you to exhale.

Asthma is commonly treated by a primary care physician. Treatment for asthma is tailored to an individual’s needs and depends on several factors, including causes, presentation, history, and response to therapy.

Here are the aims of asthma treatment:

  • prevent or minimize asthma attacks
  • control symptoms
  • eliminate visits to the emergency room
  • maintain normal activities of daily living
  • decrease night-time worsening (nocturnal asthma)
  • maintain exercise levels
  • maintain good lung function
  • minimize negative side effects of medication

Most people with asthma take medications via inhaler. Inhaled corticosteroids are preferred for long-term control of asthma. Cautious and intermittent use of inhaled long-acting β2-agonists could also help. Inhaled short-acting β2-agonists like albuterol can be used for quick relief.

After testing, oral corticosteroids, albuterol nebulizer treatment, and so forth can be used to treat asthma attacks. The specifics of treatment depend on severity. Life-threatening attacks result in hospitalization on the ICU.

Thunderstorms as an Asthma Trigger

Although the Melbourne asthma epidemic in November 2016 was the worst on record, thunderstorms have triggered similar epidemics in several cities around the world including Naples and London. Of note, because Australia is both in the Southern Hemisphere and in Australia’s temperate zone, spring occurs between September and November.

During times when there is a lot of pollen in the air, like spring, the drafts of thunderstorms can carry this pollen at ground level. In the United States, the specifics of allergy season vary by region, but it can start in February and extend to early summer. Moreover, mild winter temperatures can cause plants to pollinate early, and frequent spring rains can lead to rapid plant growth and an increase in mold.

Typically, pollen doesn’t invade the lower airways of the lungs. However during the wet conditions of thunderstorms, pollen soaks up water and ruptures by a process called osmosis. These bits of pollen become aerosolized and invade the lower levels of lungs. In people who are allergic to pollen, this exposure can cause an asthma attack and occasionally death.

The first 20 or 30 minutes of a spring thunderstorm are the most dangerous for those with pollen allergy and can lead to asthma attacks even in those who never before had one and just have hay fever. In addition to the rain and wind of thunderstorms, other factors such as lightning (electrical charges in the air) and cold could also play a role in thunderstorm-related asthma exacerbation. Specifically, electrical charges could mediate the rupture of pollen particles.

Certain experts are concerned that thunderstorms could become a public health problem for those who have hay fever and are either with or without asthma. The concentrations of pollen are increasing, and climate change is making thunderstorms and other rainy events more common.

After doing more research, experts may be able to develop early warning systems to alert those with allergies about the potential for thunderstorm-related asthma outbreaks. University of Georgia researchers are currently exploring this option.

In an article titled “Thunderstorm Related Asthma Attacks,” D’Amato and co-authors write:

"The take-home message is that patients affected by pollen allergy should be alert to the danger of being outdoors during a thunderstorm in the pollen season. Warnings should be given during the pollen season to pollen sensitive patients."

More specifically, it may be a good idea for those with pollen allergies to stay indoors and keep the windows shut during a thunderstorm that occurs during pollen season.

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Article Sources

  • Asthma. Family Practice Notebook. http://www.fpnotebook.com
  • Asthma Exacerbation. Family Practice Notebook. http://www.fpnotebook.com.
  • Barnes PJ. Asthma. In: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 19e New York, NY: McGraw-Hill; 2014.
  • D’Amato, G, et al. Thunderstorm-Related Asthma Attacks. The Journal of Allergy and Clinical Immunology. 2017.
  • Usmani OS, Barnes PJ. Asthma: Clinical Presentation and Management. In: Grippi MA, Elias JA, Fishman JA, Kotloff RM, Pack AI, Senior RM, Siegel MD. eds. Fishman's Pulmonary Diseases and Disorders, Fifth Edition New York, NY: McGraw-Hill; 2015.