"Sneeze!" Autumn has passed, and many people have begun to have symptoms such as sneezing, runny nose, itchy eyes and nose, which may be hay fever caused by pollen allergies. August 8-14 is the seventh "China Allergy Prevention Week", and the theme of this year's event is "Pay attention to the environment and breathe smoothly". Doctors remind that at this time, it has entered the high incidence season of seasonal allergies, especially pollen allergies, and it is necessary to pay special attention to prevention.
With the wind as the medium, pollen can be spread across regions
Why is the "China Allergy Prevention Week" set up in the second week of August every year? Guan Kai, assistant director and deputy chief physician of the Department of Allergies of Peking Union Medical College Hospital, said that every year in the second week of August coincides with the autumn, the summer and autumn weeds in northern China will begin to spread gas powder for up to two months, which means that tens of millions of pollen allergy patients may face symptoms such as red eyes, itchy eyes, sneezing, cough, etc. In severe cases, it will also cause skin rashes, nasal congestion and even asthma, and some patients even need emergency treatment.
"In recent years, the number of allergy patients worldwide has increased, which is related to the changes in environmental factors brought about by human social activities." Guan Kai introduced that studies have shown that China's green area is growing by more than 10% per decade, and the greening action has significantly improved the living environment of the Chinese people, but the increase in the number of vegetation has inevitably brought about an increase in plant species and the total amount of pollination, which has brought new challenges to people with allergies.
"Our hospital's allergy team has been monitoring the types and quantities of airborne pollen in downtown Beijing for a long time." Guan Kai introduced that by comparing the pollen monitoring data of the two time periods from 1983 to 1986 and 1999 to 2007, the team found that compared with 20 years ago, the total amount of tree pollen in the spring after 1999 increased significantly, and even exceeded the autumn weed pollen in terms of dispersal, accounting for 58.4% of the total annual pollen; The most significant increases were in ginkgo biloba pollen, plane tree pollen and cypress pollen.
In addition to the impact of changes in domestic vegetation, with the exchange of international trade, the pollen of invasive alien plants has begun to plague more and more Chinese people. For example, ragweed, which originated in North America, has become one of the leading causes of summer and autumn allergies worldwide. According to a survey conducted by the Department of Allergy of Peking Union Medical College Hospital and the Department of Allergy of Qingdao Fifth People's Hospital, the pollen spread of ragweed in Qingdao in 2015 was 5 times higher than in 2010.
"Although the field survey around Qingdao City did not see a large number of breeding grounds for ragweed, between 2010 and 2015, the pollen content of local ragweed increased year by year, suggesting that we should pay attention to the spread of invasive ragweed across administrative regions." Guan Kai pointed out that allergic pollen is mainly transmitted through air flow, so it has cross-regional characteristics. Research by Chinese atmospheric biology experts shows that artemisia pollen in the Beijing-Tianjin-Hebei region is produced both locally, some from neighboring provinces and autonomous regions, and even some from Mongolia, Russia, Kazakhstan and other countries.
"It can be seen that when monitoring and vegetation management of allergenic pollen, we cannot rely only on the strength of a certain region and a certain province, and may require a broader linkage participation mechanism." Guan Kai stressed.
Weed pollen, which may be more likely to induce asthma
Allergic diseases, also known as allergic diseases, are a type of disease caused by the body's abnormal immune response to allergens. Experts said that allergic diseases mainly include allergic asthma, allergic rhinitis, allergic conjunctivitis, atopic dermatitis, urticaria, food allergies, drug allergies, anaphylactic shock and so on. Allergic diseases cannot be cured, but the disease can be controlled through prevention and treatment, reducing attacks.
"The spread of pollen has obvious regional and seasonal characteristics, so the appearance of allergy symptoms is also closely related to the region and season." Guan Kai introduced that in the spring and autumn, the weather in northern China is dry and the wind is fierce, and the phenomenon of pollen allergy is more serious than in the south. In northern China, spring tree pollen (such as poplars, cypresses, birch trees, elm trees, willows, maple trees) and autumn weed pollen (such as artemisia, grass, ragweed, ground skin, quinoa grass, etc.) are the most important causes of seasonal respiratory allergies. During the pollen season, outdoor air is often explosively filled with allergenic pollen, reaching concentrations sufficient to cause allergy symptoms, not only outdoors but also indoors. At the same time, pollen can be suspended in the air for a long time, so the symptoms of pollen allergy patients may be acute and painful. In addition to the symptoms of conjunctivitis with red and itchy eyes and the symptoms of rhinitis with sneezing, 37% of allergy sufferers will develop allergic asthma within 5 years, and some patients even have anaphylactic shock due to eating plant-derived foods related to allergic pollen, which will cause serious damage to the quality of life of patients if not treated in a timely and effective manner. Therefore, it is necessary to study the clinical features of rhinitis and asthma caused by different allergens.
The team of the Department of Allergy of Peking Union Medical College Hospital found that the quality of life score of patients with allergic rhinitis was affected by the specific type of allergen: the quality of life of pollen allergists in northern China was worse than that of dust mite allergists, but the degree of quality of life impairment may not be affected by the specific IgE value of allergen blood; The proportion of rhinitis combined with asthma due to pollen allergy varies, and weed pollen may be more likely to induce asthma than tree pollen.
"This suggests that we should pay more attention to patients with hay fever in summer and autumn, be wary of their concomitant asthma, and take early prevention and treatment measures, including allergen-specific immunotherapy." Guan Kai said that in the face of pollen allergy patients, unlike the traditional organ classification department, allergologists are more accustomed to assessing the disease as a whole, by finding the causative pollen allergen, avoiding contact and preventing anti-allergy treatment for its spread season, and carrying out targeted pollen desensitization treatment to protect the patient's respiratory tract and block the progression of the disease, so that more people with allergies can breathe smoothly while enjoying the green environment.
Prevention in advance, avoidance of allergens is more effective
Experts pointed out that the treatment of autumn pollen allergy includes three elements: avoiding allergens as much as possible, receiving effective antiallergic drug therapy under the guidance of a doctor, and allergen-specific immunotherapy (commonly known as desensitization treatment).
"Affected by climatic and geographical factors, even if the same kind of pollen, there are differences in time and quantity in the distribution of different regions, so after the patient checks and clarifies the allergen in the allergy department, he can clarify the distribution characteristics of the pollen in time and space, combined with the situation of the place of residence, choose off-site treatment, that is, borrow a business trip or travel 'hide' out." Guan Kai pointed out that if there is no such condition, the following details of life should be paid attention to:
Indoor activities are mainly. Doors and windows should be closed to reduce air flow, and families with conditions can use fresh air systems or air purifiers to further reduce the density of pollen particles in the indoor unit air volume. If you are driving out, you should also close the doors and windows and use the air circulation mode.
Outdoor activities need to be protected. During the epidemic prevention and control period, whether it is to prevent the new crown virus or anti-pollen allergy, it is necessary to wear masks and anti-pollen glasses when going out. Experiments have shown that wearing pollen glasses can reduce the contact of pollen particles with the conjunctiva of the eye by about 65% compared with not wearing anti-pollen glasses; Wearing a more comfortable anti-pollen mask can effectively adsorb and filter autumn pollen, which has a good protective effect on the respiratory tract of allergy patients.
Pick a time for outings. Pollen concentrations tend to be higher in the afternoon during the day. If you must go out, try to go out at the wrong time, try to travel in the early morning, evening or after a gentle drizzle with the lowest pollen concentration. It should be noted that thunderstorms have poor cleaning ability to pollen particles in the air, and can make pollen particles swell and break into small particles with stronger sensitivity, so do not go out before and after thunderstorms.
Pay attention to personal cleanliness. During the epidemic period, patients need to frequently remove masks and glasses to wipe their nose or tears due to pollen allergies, at this time, pay attention to personal cleaning, and wash their hands once every time they touch the outer layer of the mask. It takes 20-30 seconds to wash your hands each time, and the finger slits should also be soaped carefully and rinsed with running water. In general, wool clothes are more likely than cotton and chemical fiber clothes to generate electrostatic adsorption pollen, thereby carrying pollen indoors, so try to choose clothes with smooth surfaces when going out. At the same time, wash your hair and change your coat in time after returning home to remove the pollen particles adsorbed on your hair and clothes.
"Some people ask, why do you wear a mask or have allergy symptoms? Because no mask of any style can intercept all the pollen in the air 100%. In addition, pollen will also enter the room with the air, and the patient can still inhale pollen by removing the mask indoors. In addition to inhalation through the respiratory tract, pollen can also cause allergic reactions through skin contact such as the face, neck, and hands. Guan Kai said that if everyone has taken preventive measures in accordance with the protection recommendations and still has allergy symptoms, it is necessary to use effective and standardized anti-allergic drugs under the guidance of professional doctors.
Commonly used drug types are: nasal or inhaled glucocorticoids, nasal or oral antihistamines, oral antileukotrienes, decongestants, traditional Chinese medicines, etc. Each patient's specific medication regimen is not static, and a professional doctor needs to decide on medication according to the patient's pollen allergy and actual symptoms and adjust it in a timely manner. During an outbreak, patients with first-time onset or mild symptoms can also be given over-the-counter medications under the guidance of a professional pharmacist, or if they are ineffective or ineffective for 1 to 2 weeks, they should go to an allergy department.
Desensitization therapy may be considered if patients with autumn pollen allergy have a long duration of symptoms each year, are not satisfied with medication control, or are unwilling to use medications for a long time. Doctors will follow the degree of the patient's allergen skin test response, sequentially select the increasing concentration of pollen vaccine for subcutaneous injection, after reaching the target maximum concentration, and then use a fixed dose to maintain and observe the efficacy, the total course of treatment is usually not less than 3 years, the efficiency can reach about 80%. (Wang Meihua)
Source: People's Daily Overseas Edition