Asthma is an allergic disease, the internal cause of the disease is “allergy”, and the external cause is various allergens. The first principle of treatment is to get rid of allergen exposure. Many patients diagnosed with asthma for the first time will naturally think: identify the type of allergen as soon as possible and try to avoid it in the future so that asthma can heal itself. Is it really that simple? Allergies are genetically determined, genetically predisposed, and inherent. However, the timing of allergy symptoms, the location of allergy symptoms and the severity of symptoms are influenced by many acquired environmental factors. This is why some people develop allergic rhinitis and eczema in childhood, while others develop symptoms only at the age of 50 or 60, and some have severe symptoms while others have mild symptoms. There are many kinds of allergens, the following are common allergens in life: 1, mites: microscopic dust mites are about 0.33mm long, it grows and multiplies by eating the skin scales shed by the human body every day, so there are more dust mites in the bed, which is also the cause of more asthma attacks at night in children. Dust mites grow best in warm and humid seasons, so dust mite avoidance measures should pay attention to reducing the relative humidity, in addition, because dust mite dead body debris deposited in the dust of dead corners not normally cleaned, so there are generally a large number of dust mite antigens in the old dust at home. 2, indoor fungus: the main allergenic human body is mold. Indoor fungus level and the age of housing, heating system and the use of humidifiers and air conditioning units are related. Dark, damp, poorly ventilated living room, especially the basement is the ideal place for fungal growth, followed by the bathroom and kitchen, humidifiers and air conditioning units can also become a place for fungal growth, the home environment is damp, overcrowded home easily cause asthma in children. 3, silkworm: silk and cotton are mainly used as fillers for winter clothing, being woven into sweaters and carpets, so it is an important cause of asthma attacks in winter. Silk, due to multiple processing rarely induces allergies. Silkworms are completely metamorphic insects, and there is cross-reactivity between silk and other forms of silkworms, such as cocoons, young silkworms, silkworm urine, silkworm pupae and silkworm moth scales, so people allergic to silk can be allergic to any form of silkworms. 4. Animal-related allergens: Indoor animals, especially dogs and cats, are common causes of allergic rhinitis and asthma. When dogs or cats enter the home, patients allergic to them can develop within minutes. Woolen sweaters and pants made of wool have been processed several times, and allergenicity has been greatly reduced and rarely causes allergies. Cockroaches, which are commonly found in kitchen cabinets and bathrooms, are also common inhalation allergens. However, it should be noted that irritating chemical pesticides can also induce allergic symptoms. 5, pollen: pollen is generally common outdoors, trees, grasses and weeds three major types of plant pollen is spread by the wind, scattered in the air of these phoenix vector pollen is the main source of airborne allergens. These pollens are fragrance-free, large in quantity, light in weight, and extremely widespread, and can drift with the wind to high altitudes and to distant fields and towns, and are the main pollen that induces allergies. Wind-borne pollen in spring mostly comes from trees, such as pine, cypress, poplar, acacia, willow, birch and other pollen in the air for a short period of time, more than ten days can pass, causing lighter symptoms and a shorter duration. Late spring and early summer wind-borne pollen is mostly from pasture. Wind-borne pollen in late summer and early autumn comes from weed species, and is most common in China with Artemisia absinthium. Grass pollen drifts for a long time, causing heavy symptoms, and the symptoms last for a long time, about a month or so. And 90% of hay fever is caused by pollen in summer and autumn, so many kinds of allergens, some allergens such as: dog and cat fur, it is easy to avoid. However, most allergens, such as pollen, mites, and fungi, are highly concentrated and widely distributed, so it is difficult to completely avoid them. Moreover, many patients are sensitive to multiple allergens, so it is difficult to expect to cure allergic diseases through the method of complete disconnection from allergens. Given this, is it possible to get rid of these allergens completely through desensitization? Desensitization therapy, also known as specific immunotherapy, is practical and can stall the worsening of symptoms and prevent the development of allergy to new allergens. Desensitization involves making injections or oral preparations of known allergens and giving them subcutaneously or orally and sublingually on a regular basis to create immune tolerance in patients, which can reduce the symptoms and attacks of allergy. The complete course of desensitization therapy takes 3 to 5 years, and several studies have demonstrated that successful desensitization therapy can free patients from drug dependence for up to 8 years. However, there are only a limited number of allergens that can be desensitized, and the only internationally recognized technically mature desensitization reagents are dust mites and some fungi, which means that desensitization can only be successful if the patient is sensitive to only these two allergens. However, most allergic patients are allergic to multiple allergens at the same time, and desensitization to only two allergens is as effective as one can imagine. This is the reason why desensitization is not the preferred method of treatment for allergic diseases at this time. So, is there any value in checking for allergens and performing desensitization therapy or not? Of course there is. When the first diagnosis of asthma is made, patients should check the allergen types in detail so that they have a good idea of what to expect. When there are easily avoidable types of allergens such as cat hair and dog hair in your allergen profile, you should avoid them completely in the future. Keep doors and windows tightly closed. When you find out that you are allergic to mites only, you should take desensitization treatment.