What about pollen allergy in spring? Keep this guide to hay fever prevention.

According to the report of News Hyperlink of Voice of China, CCTV, before and after Qingming Festival, many people had symptoms such as sneezing, runny nose, watery eyes and itchy skin, which may be caused by pollen allergy.

Don’t underestimate hay fever. In extreme cases, hay fever may even be life-threatening. What exactly is pollen allergy? Which flowers’ pollen can cause allergies? How to effectively prevent hay fever?

Hay fever: a systemic immune response

In most parts of China, there are two peak periods of hay fever every year: the spring peak from April to June and the autumn peak from August to September. In order to make people with allergic constitution better prevent pollinosis, meteorological departments in many places also launched "Pollen Allergy Meteorological Index Forecast" or "Pollen Forecast" in spring and autumn.

Pollen allergy is not only uncomfortable, but also potentially dangerous. The scientific name of "pollen allergy" is "seasonal allergic rhinoconjunctivitis". The most common symptoms include uncomfortable nose, sneezing, runny nose, itchy eyes, watery eyes, swollen eyes, etc. Some people also have skin allergies, cough, and even asthma in severe cases. Some patients have diarrhea due to taking pollen preparations. Ren Huali, deputy director of the Department of Allergy of Beijing Electric Power Hospital and a doctor majoring in allergy at Peking Union Medical College, told News Hyperlink that allergy is a systemic immune response, which can also cause shock in severe cases.

Allergens: mainly tree pollen and weed pollen.

In order to avoid allergies, some pollinosis patients stay away from flowers. However, Yue Honghong, deputy director of the Department of Rheumatology and Immunology of the Armed Police General Hospital, said that the pollen of common beautiful flowers is often not an allergen; If there is no discomfort after contact, you don’t have to be too afraid.

Compared with peach blossoms and cherry blossoms, tree pollen and weed pollen are more likely to cause allergies.

In fact, the main causes of allergies are tree pollen and weed pollen — — Or, it’s pollen from plants that don’t look very good. In northern China, the allergens of spring pollen allergy are mainly tree pollen, such as poplar, cypress, birch, elm, willow and maple. The most common pollen allergy in autumn usually comes from weed pollen, including mugwort, humulus scandens, Chenopodiaceae, ragweed and so on. The flowers of these plants have degenerated, are generally small and inconspicuous, and have no fragrance and nectaries. When they reproduce, they mainly rely on wind to spread pollen, so they are called "wind-borne flowers".

When the pollen of "wind-borne flowers" spreads in the air, the amount is usually very large. The greater the amount of pollen, the longer it floats in the air, and the more likely it is to be touched by people with allergic constitution, thus causing allergic reactions. According to Ren Huali, in mid-April, the common catkin allergy in some northern areas was actually caused by pollen — — Catkin is the seed of pollen, and what causes allergies is invisible and intangible pollen.

Pollen of Sabina vulgaris is one of the main allergens (photo by Zhang Zhixiang)

Treatment: Prevention in advance is more effective than medication after the attack.

Wang Lianglu, director and chief physician of the Allergy Department of Peking Union Medical College Hospital, suggested that allergic patients should take preventive measures in advance, which is more effective than taking drugs after the attack. Rhinitis and asthma caused by pollen allergy have a definite attack time, so patients can take preventive drugs accordingly. If pollen allergy causes obvious conjunctival symptoms, sodium cromoglycate can be used about two weeks in advance; The symptoms of nasal discomfort are particularly prominent, and you can spray hormones one week in advance; People with severe asthma symptoms can inhale hormone plus long-acting &beta one week in advance; Receptor agonists. Pollen allergy is caused by IgE antibody, and patients can also inject anti-IgE antibody two months in advance, which can play a good preventive role.

If local conditions permit, you can also go to the Allergy Department to identify allergens. After you know what pollen you are allergic to, you can take corresponding desensitization treatment, which is called "immunotherapy" academically. Generally speaking, the course of immunotherapy takes 3 to 5 years, and the obvious effect will be seen after 2 years of treatment. After about 5 years of desensitization treatment, the allergic symptoms of patients in pollen season will be obviously alleviated, or even no symptoms will appear, and the curative effect can be maintained for a long time. (Reporter: Yang Yang Liu Fei)