Four people are dead and another 1,870 people had to be treated for shortness of breath when a rare condition known as “thunderstorm asthma” struck the Australian city of Melbourne earlier this week.
It sounds weird, but thunderstorm-induced asthma is actually a thing. As the Associated Press is reporting, a storm rolled through Melbourne this past Monday, causing rain-soaked ryegrass pollen to explode and disperse over the city. The sudden influx of pollen triggered asthma attacks among many of the city’s residents, including people who had never suffered from asthma before.
Four people died as a result, while first responders had to attend to more than 1,870 cases. That’s about six-times the usual workload for a Monday evening. Seven patients had to be admitted to the Royal Melbourne Hospital’s intensive care unit.
George Braitberg, who heads the hospital’s emergency department, compared the scene in the hospital on Monday night to a war zone, telling local television, “I’ve been an emergency physician for about 35 years, worked in a number of hospitals, and I can say, hand on heart, that I have not seen this before.”
The Australasian Society of Clinical Immunology and Allergy says it’s reasonable to think that rain would alleviate the symptoms of hay-fever and asthma by “washing” pollen out of the air, but paradoxically, it can make some people feel worse:
Some grass allergen (like ryegrass allergen Lol pIX) is located on the surface of starch granules within pollen grains. A single pollen grain contains up to 700 starch granules of 0.6 to 2.5 um (small enough to reach the lower airways in the lung). When it rains or is humid, pollen grains can absorb moisture and burst, releasing hundreds of small allergenic particles that can penetrate deep into the small airways of the lung.
Not everyone who gets thunderstorm asthma has had it before. They have normally had severe pollen allergic rhinitis (hay fever) and most have been found to be allergic to ryegrass. Presumably the massive load of small allergenic particles being inhaled straight into the lung trigger these attacks.
In Melbourne’s case, the level of rye-pollen particles was more than double the level that’s considered high. Other documented cases of thunderstorm asthma have been reported in Canada, Italy, and the United States. In 1994, a storm blew through London, sending 640 residents to the emergency room.