细胞(嗜酸细胞)浸润,容量血管扩张和由于血管通透性增加而致的粘膜肿胀是花粉症呼吸道粘膜的主要病理改变。此种病理改变反映了炎症反应的基本特征,因之称为变应性炎症反应。与感染性炎症反应不同,这种炎症反应中嗜酸细胞浸润占优势。除花粉症外,大多数常年性鼻炎和鼻息肉也表现为变应性炎症反应。支气管哮喘除文气管粘膜有变应性炎症反应外,并伴有支气管平滑肌痉挛等。在特异性变应性反应和变应性炎症反应之间有一个必要的连结物质,即介质系统。Ⅰ型变态反应中慢反应物质,特别是组胺引起血管扩张和分泌物增多。嗜酸细胞趋化因子引起嗜酸细胞在血中增多和在呼吸道粘膜局部浸润,血小板活化因子引起血流紊乱,如血液凝固、栓塞或出血等。这些介质称为原发的介 Cell (eosinophil) infiltration, volumetric vasodilatation and mucosal swelling due to increased vascular permeability are the major pathological changes in the respiratory mucosa of hay fever. This pathological change reflects the basic characteristics of the inflammatory response, which is called allergic inflammation. Unlike infectious inflammatory responses, eosinophil infiltration predominates in this inflammatory response. In addition to hay fever, most perennial rhinitis and nasal polyps also show allergic inflammation. Bronchial asthma in addition to the tracheal mucosa with allergic inflammation, and accompanied by bronchial smooth muscle spasm. There is a necessary link between a specific allergic reaction and an allergic inflammatory reaction, the media system. Type I allergic reactions slowly react with substances, especially histamine, causing vasodilation and increased secretions. Eotaxin causes eosinophils to proliferate in the blood and to local infiltrate in the respiratory mucosa. Platelet-activating factors cause blood flow disorders, such as blood clotting, embolism, or bleeding. These media are called primary mediations