Allergic rhinitis, also known as allergic rhinitis, is a chronic inflammatory disease of the nasal mucosa caused by IgE-mediated release of mediators (mainly histamine) in atopic individuals after exposure to allergens, with the involvement of a variety of immunoreactive cells and cytokines. The disease is often clinically divided into perennial allergic rhinitis and seasonal allergic rhinitis, the latter also known as “hay fever”. Although allergic rhinitis is not a serious disease, it can affect the patient’s daily life, study and work efficiency, and cause a heavy economic burden, and can lead to bronchial asthma, sinusitis, nasal polyps, otitis media, or occur simultaneously with allergic conjunctivitis. What are the pathological causes of allergic rhinitis? It is known that allergic rhinitis is often associated with exposure to allergens. Studies have shown that genetics and the environment are also important factors in allergic rhinitis. There are three main ways in which allergens act on individuals: (1) Inhalation allergens: indoor allergens such as dust mites, animal fur or plant-derived allergens; outdoor allergens including pollen and fungi, etc. (2) Ingested allergens: common ones such as milk, eggs, meat, fish, shrimp and other seafood, and certain drugs. (3) Direct contact with allergens: such as cosmetics, soap, paint and certain topical solutions. 2, genetic factors allergic diseases are a chronic developmental process, related to genetics: from a clinical point of view, patients with allergic rhinitis are often accompanied by a significant family history. From the 1970s onwards, survey data on family lines and twins can confirm this conclusion. In addition, this genetic phenomenon is more evident in single-fertilized twins than in double-fertilized twins, and children with certain genes may be particularly sensitive. 3, environmental factors: (1) air pollution: outdoor pollution mainly from motor vehicles and atmospheric pollution components, such as ozone, nitrogen oxides and SO2. Indoor pollution mainly from formaldehyde, toluene, etc. (2) Infection factors: “health hypothesis”: that the increase in allergic diseases is the result of a decrease in infectious diseases. The theory is based on bacterial infection or exposure to the products of bacteria and stimulate the response of T helper type 1 cells (Th1), which generates inhibition of the responsiveness of Th2 and achieves a reduction in the incidence of allergic diseases and asthma. In addition, it has been reported that viral infections can produce similar effects. However, the scientific basis and the exact immunological mechanism of these assumptions have not been fully confirmed.