Thunderstorm Asthma

Although not frequent, severe springtime thunderstorms have been linked to asthma attack epidemics. Last year, more than 8,500 patients overwhelmed hospitals and emergency personnel during a thunderstorm on November 21 (Australia’s springtime) in Melbourne.

So, what happens during a thunderstom that causes asthma to get so bad?

Pollen is carried in the wind, so pollen counts tend to be higher when the weather is dry and windy. Pollen grains are microscopic and can get into the nose and eyes causing typical allergy symptoms, but they are too large to get into the small airways of the lungs. However, during a rainstorm, the pollen grains can swell, causing them to burst. During a thunderstorm, pollen can be taken up into the air and the swollen pollen grains combined with the electricity in the air during a thunderstorm can rupture the pollen grains, releasing allergenic proteins that can penetrate into the bronchial tubes.

Thunderstorm asthma seems to be only caused by grass pollen and mold, and usually only during the spring. It can be severe enough to cause an asthma attack even in people without asthma, but who are allergic to grass. The good news is that these episodes are not common, and if grass or mold allergic persons remain indoors with the windows closed during a very severe thunderstorm, they will not be affected.