外源性变应性肺泡炎(Extrinic Allergic Alveolitis)是职业性肺病之一种,随工农业的发展,本病逐渐多见,是因吸入有机粉尘,包括真菌孢子的抗原性物质引起,以肺泡壁,细支气管变态反应性炎症为主的综合病征。是一类病理、临床和X线表现相似的致纤维性肺泡炎(Fibrosing Alveolitis)的一种。患者多在生产环境中吸入致敏粉尘,引起发热、咳嗽、气喘、乏力及肺部病变等症状。慢性期可引起肺弥漫纤维化,又称职业性哮喘或过敏性肺炎。一、病因和发病机理本病的发病机理,需要有以下条件:1.抗原性质;2.个体免疫学反应性;3.组织器官的反应性。因此,吸入抗原未必均发病,或仅有血清特异性沉淀抗体阳性。部分具上述条件的患者始有症状及肺部病变。引起本病的免疫学机制有:1.Ⅲ型变态反应:为本病发病机制的主要依据,表现为吸入抗原至出现症状的时间为4～8小时。以荧光抗体法检查肺部病变 Extrinic allergic alveolitis (Extrinic Allergic Alveolitis) is a kind of occupational lung disease, with the development of industry and agriculture, the disease gradually more common, is due to inhalation of organic dust, including antigenic substances caused by fungal spores to alveolar Wall, bronchial allergic inflammation based syndromes. Is a kind of pathological, clinical and X-ray findings similar to fibrosing alveolitis (Fibrosing Alveolitis) a. More patients in the production environment inhaled sensitized dust, causing fever, cough, asthma, fatigue and lung disease and other symptoms. Chronic phase can cause diffuse lung fibrosis, also known as occupational asthma or allergic pneumonia. First, the etiology and pathogenesis The pathogenesis of this disease requires the following conditions: 1. The nature of the antigen; 2. The individual immunological reactivity; 3. Organ tissue reactivity. Therefore, the inhaled antigen may not all be present or only the serum-specific precipitating antibody is positive. Some patients with the above conditions began to have symptoms and lung disease. The immunological mechanisms that cause this disease are: 1. Ⅲ type allergy: the main basis for the pathogenesis of this disease, manifested as inhaled antigen until symptoms time is 4 to 8 hours. Fluorescent antibody test for lung lesions