CURSED POLLEN: The stormy episodes of the last few days have caused an increase in emergency room visits for respiratory distress
- In recent days, violent storms have broken out in France, causing an increase in hospitalizations for cases of respiratory distress.
- Monday evening, 13 departments were still on orange alert, and the weather still looks unstable on Tuesday, while new stormy episodes are still expected.
- As World Allergy Week takes place, we focus on storm asthma, or how stormy episodes have the side effect of causing exacerbated reactions in some people allergic to pollen.
It will thunder, and it will cough. After a weekend dotted with numerous stormy episodes, thirteen departments ranging from Center-Val-de-Loire to Burgundy, Champagne and Lorraine, remained on orange alert Monday evening for thunderstorms that could be violent, locally accompanied by hail and strong gusts of wind up to 80/90 km/h, even very locally 100 km/h. Unstable weather still on the program this Tuesday, with a new stormy deterioration that will affect a large part of the country, forecasts Meteo France.
A concomitant phenomenon to the storms this weekend, an increase in emergency room visits for respiratory distress has been observed. Many patients were treated for severe asthma attacks, directly related to the weather. They were taken from what is called “storm asthma”. Kezako?
On the site of the National Aerobiological Risk Monitoring Network (RNSA), the latest allergy risk map in France is mostly adorned in red. “The risk of allergy will be medium to high for grass pollens which remain present throughout France to bother allergy sufferers in favor of hot and sunny weather”. Nothing unusual in this summer period.
“What is problematic, however, is that we are in a long period loaded with pollen, without respite since the arrival of birch pollen in December, underlines Isabella Annesi-Maesano, director of research at Inserm and epidemiologist allergic and respiratory diseases. To draw a parallel with another meteorological phenomenon – water bombs, we are subjected to pollen bombs, which are present over a long period and in large quantities. The combination of this phenomenon with this special weather, marked by intense heat and stormy episodes, gives rise to the risk of thunderstorm asthma”.
The storm before the calm
“It is possible that allergy sufferers would be bothered at the start of certain heavy thunderstorms because the concentration of pollen would increase rapidly near the ground with the strong downdraft winds which bring grass pollen from the upper air layers to the air layers near the ground. ground, confirms the RNSA. Then, the many storms that will cross the country will be accompanied by heavy showers of rain that will give a little respite to allergy sufferers by flattening the pollen on the ground”. But before savouring the return to calm, those with allergies are at first risk of suffering from the stormy wind that precedes the storm. In practice, “before it rains, the beginning of a stormy episode is manifested by strong gusts, explains Isabella Annesi-Maesano. The air pressure changes, whirlpools form, and the wind, which intensifies, will stir up the pollen which, with the high humidity in the air, will become waterlogged”.
But by what mechanisms can the storm make the pollens more virulent? “The pollen bombs fragment: by gorging themselves with water, the pollen explodes, the outer membrane of the pollen grain – the exine – opens and releases submicron particles containing more allergens, details the epidemiologist. Then everything falls back. However, contrary to the classic pollens which stop at the level of the nose, affect the nasal mucosa and give rise to rhinitis, or hay fever, in the event of allergic ground, if they are inhaled, these submicron particles penetrate deeply into the bronchial tree and can trigger a very virulent thunderstorm asthma attack”.
“It must be scary”
And “if many seem to discover this phenomenon, storm asthma is not a new phenomenon: it has been described by other countries for twenty years, especially in the United Kingdom or Italy, adds Isabella Annesi -Maesano. And at the end of 2016, during the austral spring, there was a massive thunderstorm asthma episode in Melbourne, Australia, during which 9,000 people went to the emergency room, and 9 lost their lives. This weekend, especially in Ile-de-France, we observed at the same time as the violent storms a peak in emergency rooms for cases of respiratory distress ”.
And “if until now, these stormy asthma attacks affected people with allergic conditions, the novelty we are seeing in France is that it now also affects people with well-controlled asthma, followed by a doctor and under treatment, worries the epidemiologist. We see asthmatic but not allergic patients who, due to the excess of pollen and submicron particles due to the storm, have had an attack. The body can no longer manage. However, when we know that stormy episodes increase with global warming, this must be scary”.