These common substances may be triggers for asthma. Are Shanghai citizens prone to developing "thunderstorm asthma"? In daily life
Recently, after a rainstorm, the number of patients with cough, wheezing, dyspnea and dyspnea in emergency department of hospitals in Hohhot, Inner Mongolia soared. Doctors refer to the bronchial asthma that causes these symptoms as "thunderstorm asthma".
Why can thunderstorm weather cause asthma? What are the common causes of asthma attacks? Autumn is approaching, and Cha Qiongfang, Deputy Chief Physician of the Respiratory Department at Renji Hospital affiliated with Shanghai Jiao Tong University School of Medicine, reminds us to understand the common allergens and triggering factors of asthma, and to spend autumn and winter safely and healthily.
What are the common triggering factors for asthma?
"The essence of 'thunderstorm asthma' is that during thunderstorm weather, high concentrations of pollen are inhaled into the respiratory tract, leading to allergic asthma." Cha Qiongfang explained that strong convective air before thunderstorm weather causes pollen to enter the clouds, and lightning in the clouds causes pollen particles to burst, releasing smaller particles that return to the ground with rain. The smaller the pollen particles, the easier it is for them to enter the respiratory tract. At the same time, the strong electric field generated by thunderstorm weather also makes the particles released by pollen particles more allergenic, making it easier to induce asthma.
It has always been believed that asthma is a typical allergic disease. However, nearly 30 years of research have found that the essence of asthma is chronic inflammation of the airways, with pathological and physiological characteristics mainly characterized by airway hyperresponsiveness and airway remodeling. Allergic asthma is an important type of asthma, accounting for 60% to 80% of asthma.
Cha Qiongfang said that there are many triggering factors for asthma. Common examples include exposure to allergens, viral or bacterial infections, seasonal or temperature and pressure changes, exercise, medication, emotions, etc. "Asthma caused or induced by contact with allergens is called allergic asthma." The common allergens of allergic asthma are inhalation allergens such as dust mites, pollen, mold, cat hair, dog hair and its dander, perfume, paint smell, etc; Ingestive allergens such as nuts, eggs, milk, shrimp, crabs, etc.
Dust mites are also one of the main allergens of allergic asthma in China. Allergic reactions to dust mites can occur in various age groups and seasons. Dust mites are suitable for living in warm and humid environments and can reproduce throughout the year. Common species include house dust mites, dust mites, and tropical mites. "House dust mites mainly breed in carpets, sofas, bedding, mattresses, pillowcases, plush toys, and clothing in households' bedrooms. Dust mites inhabit poultry feed, warehouse dust, granary and textile factory dust, building dust, carpets, and filled furniture. The allergens produced by dust mites mainly come from their secretions, excrement, and debris."
What is thunderstorm asthma?
Another common allergen of allergic asthma is pollen, and seasons with high pollen concentrations can easily trigger allergic asthma. "Pollen in China is mainly divided into spring pollen and summer and autumn pollen. Spring pollen is concentrated in March to May, and is common in cypress, French wutong, ash, birch, poplar, willow, etc.; summer and autumn pollen is concentrated in August to September, and is mainly Artemisia pollen, humulus, ragweed pollen, etc."
Cha Qiongfang explained that before the "thunderstorm asthma" in Hohhot, the concentration of urban pollen had reached a high level, mainly composed of Artemisia pollen, followed by Chenopodiaceae pollen. "Under the influence of thunderstorms, it ultimately leads to acute attacks of allergic asthma in many people. However, she reminds that acute attacks of allergic asthma are actually more common in the spring and autumn seasons, and high pollen concentration is the main factor. In addition, the large temperature difference in the morning and evening during the spring and autumn seasons can also easily trigger asthma.".
Of course, compared to pollen induced asthma, pet allergies are more common. With the improvement of citizens' living standards and the impact of aging and low birth rates, more and more families are keeping pets, and the number of pet allergies is also increasing, which is related to contact with cat hair, dog hair, or their dander. This type of allergen is distributed in indoor dust, furniture decoration, and also in public places. It is mainly transmitted through the air and can remain in the air for a long time.
Will Shanghai experience "thunderstorm asthma"?
Cha Qiongfang said that the typical manifestation of allergic asthma is paroxysmal cough, chest tightness, shortness of breath, or difficulty breathing after exposure to allergens. After detachment from the allergen, it can improve on its own or after medication, and wheezing sounds can be heard in the lungs during the attack. But she specifically pointed out that some asthma patients have atypical symptoms, only showing cough, chest tightness, or no symptoms, only airway hyperresponsiveness, clinically referred to as cough variant asthma, chest tightness variant asthma, or insidious asthma. "If this type of atypical asthma is not well controlled for a long time, it will eventually develop into typical asthma."
In addition to allergic asthma in the respiratory tract, many patients with allergic constitution often have concomitant allergic rhinitis, allergic conjunctivitis, allergic dermatitis, vascular urticaria, etc. Allergens can be identified through hospital related allergen testing to avoid contact or ingestion.
Cha Qiongfang said that after Shanghai enters autumn, the temperature difference between morning and evening will increase, and the concentration of pollen in autumn will also increase. Citizens with allergic asthma should take early prevention measures. "In prevention, the most important thing is to avoid contact with allergens, including inhaling dust mites, pollen, cat hair, dog hair, mold, etc. When going out during the pollen season, wear a mask." Finally, she said that many people are worried about whether Shanghai will also experience "thunderstorm asthma", which is actually excessive. "Due to Shanghai's unique geographical location, low altitude, close to the sea, southeast wind and typhoon weather in summer, it is easy to form thunderstorm rainstorm, while thunderstorm weather is less in autumn, so the incidence of 'thunderstorm asthma' is low." If thunderstorm weather occurs, it is recommended to close doors and windows to reduce pollen blowing indoors; Reduce the frequency of going out after a thunderstorm and wear a mask when going out; Citizens diagnosed with asthma should adhere to standardized medication during thunderstorm weather to prevent acute asthma attacks.
