”Ah-choo, ah-choo, ah-choo, ……” Ms. Wang got up early in the morning and sneezed several times in a row, she herself felt strange, did she catch a cold? The company’s main business is to provide a wide range of products and services to its customers. Then, her nose itched again, and then she sneezed and wiped her nose. This morning in early spring and March, Ms. Wang spent her time in the itchy nose, sneezing and clear water snot. Facing the waste tissue full of paper Lou, she felt the pain of messing with people, and after taking a cold medicine, she felt a little more comfortable in her drowsiness. Meanwhile, the cypress trees all over Beijing were taking advantage of a rare rain and snow that had just passed, absorbing enough water and sunlight to spit out new green and unfold their buds. From a distance, the cypress trees look yellow all around, and when the wind blows, the pollen is sprinkled all over them and scattered with the wind. The pollen is everywhere, the crowd will appear like Ms. Wang sneeze constantly, runny constantly “cold” patients. What is this all about? In fact, this scene began as early as 200 years ago in Europe, the early called “cush fever”, now called “allergic rhinitis”. In recent years, with the acceleration of industrialization in China, the incidence of allergic rhinitis has gradually increased and has become a common disease. This disease is similar to a cold, but it is not a cold. Ms. Wang had the above-mentioned nasal symptoms because she was allergic to cypress pollen. So how does allergic rhinitis develop? As the name suggests, people with allergic rhinitis first develop a nasal allergic reaction to a specific allergen. What allergens are around us? The four main categories include: pollen from trees and weeds, dust mites, molds, and animal dander. The spread of major allergenic pollens is greatly influenced by the seasons. In the north, from mid-March to mid-April is cypress pollen, from early April to mid-May is pollen from oak, birch, French sycamore, etc., from May to June is pollen from pasture grasses, and from August to October is pollen from weeds such as Artemisia and Humulus, until frost comes and the air is no longer filled with pollen. Allergies caused by dust mites are different. Since dust mites are widely distributed in our bedding, pillows and sheets, they are in close contact with us every day, and the allergy symptoms caused by its metabolites do not distinguish between seasons, but are present all year round. Molds are similar to dust mites and also cause perennial symptoms. The dander of pets such as dogs and cats has to be in close contact with the pets in order to cause the symptoms of allergic rhinitis, so the treatment is relatively simple and can be cured completely by avoiding contact with them. How do allergens cause the symptoms of itchy nose, sneezing and clear runny nose? Let’s still take Ms. Wang’s cypress pollen allergic rhinitis as an example to answer this question. The cypress pollen distributed in the air entered the nasal cavity with the airflow of Ms. Wang’s whistle and landed on the mucous membrane on the surface of the nasal cavity. If it were other people’s mucous membranes, the arrival of cypress pollen would not cause any reaction in the mucous membranes, because they are familiar with each other and are at peace with each other. But Ms. Wang’s nasal mucosa is different. The lymphocytes in the mucosa are alerted and react defensively in the face of the raging pollen. The lymphocytes in the human body are divided into two main categories, T lymphocytes and B lymphocytes. t lymphocytes are like sentinels, once they find the pollen invasion of the nose, they will take the initiative to check the identity and properties of the offending pollen and relay it to the B lymphocytes. the B lymphocytes are the “weapons factory”, after receiving the alarm to start the war mode. The B lymphocytes are the “weapons factory”, and when they receive the alert, they start the war mode, reproduce themselves to increase their number, and produce a large number of weapons for the subsequent “combat command center”, the mast cells. If the mast cells capture the same pollen again, they will give the “order of battle” to the blood vessels and nerve endings in the nasal cavity to reject the enemy, causing nasal itching and continuous sneezing by stimulating the nerve endings, so that the strong nasal airflow will blow away the pollen in the nasal cavity; at the same time, the blood vessels in the nasal cavity will dilate and increase permeability, releasing a large amount of secretion to wash away the mucous membrane. Flushing away the allergens adhering to the mucous membrane. The constant inhalation of pollen produces constant nasal resistance: itching, sneezing and runny nose, until the pollen season passes and no longer appears in the nasal cavity, then the attack is over. How do we check for specific allergens? Each person with allergic rhinitis has a different constitution and different allergens, which requires a specific analysis of the problem. How to analyze it? Currently there are two main ways to start: blood tests and skin allergen testing. We can find out the relative allergens by taking blood to check the characteristics of the “weapons” made by the B lymphocytes carried in the blood. Also, since the skin and mucous membranes are similar and can have similar allergic reactions to the same allergens, we can also use the skin of the patient’s arm or back as a “test bed” and expose the skin to a series of known allergens and observe the reactions to determine which allergens the patient is allergic to. So, we see patients with allergic rhinitis in the hospital roll up their sleeves, expose both forearms, and get tested for nearly 20 allergens. Whenever an allergen or allergens are found to cause abnormal erythema or even blisters and irregular pseudopods, it can visually help us determine what the allergen is and how severe the allergic reaction is caused. How should I treat the allergen after it is identified through the examination? Identifying the allergen can help us both to confirm the diagnosis of the disease and to treat it. As mentioned earlier, if we are allergic to the dander of pets such as dogs and cats, we can avoid the disease by avoiding contact with them. In the case of pollen that causes allergies, we can also selectively avoid the onset of symptoms by changing our living environment to escape from the pollen distribution area, but this has a significant cost in terms of learning to live and work. Similarly, we can mitigate dust mite exposure by frequently changing the sheets and bedspreads and bedding and pillows, but also with little success. What to do? The good thing is that we still have medications that can inhibit the resistance of the nasal mucosa. We have anti-allergy drugs, nasal spray hormones and other drugs that can effectively reduce or even completely control the allergic symptoms of allergic rhinitis, to live symptom-free and restore free whistling. Of course, surely you have heard of desensitization treatment for specific allergens. This is considered by the World Health Organization to be the only treatment that can change the course of the allergen. We can give the body a small amount of the allergen at the beginning and increase the dose in the following days, so that the body gradually develops tolerance to the allergen, thus making the T-lymphocytes in the nasal mucosa oblivious to it and avoiding the corresponding allergen symptoms. This is a very good treatment option with good efficacy, but at present, desensitization can only be performed for some common allergens. There is nothing that can be done for other allergens. Let’s go back to the case of Ms. Wang mentioned at the beginning of the article. Although Ms. Wang took the anti-cold medicine on her own and the anti-allergic ingredients in the medicine relieved her discomfort, within a few hours, the symptoms appeared again. She couldn’t just take any medicine, so when Ms. Wang went to the hospital to seek help from her doctor and was diagnosed with allergic rhinitis caused by cypress pollen, she accepted the doctor’s advice and used nasal spray hormone to control her symptoms. She also got into the habit of taking notes every day, recording her nasal symptoms for the next month or so, and figured out the interval between attacks of her allergic rhinitis, so that she could have a good idea of what to expect and not worry about the attacks in the coming year. She understood that she could use the medication in advance to avoid the annoying symptoms of itchy nose, sneezing and blowing clear nasal mucus in the coming year.