近 2 0年来的研究使人们认识到支气管哮喘的本质是较大支气管的慢性炎症 ,吸入皮质激素和支气管扩张剂可以使疗效显著提高 ,预后改善。但是有一小部分病人 ,单纯吸入治疗尚难以控制病情 ,需辅以全身用药。这促使人们设想病变可能涉及吸入药物难以到达的小气道和肺组织。自 90年 Recent 20 years of research to make people realize that the essence of bronchial asthma is a larger bronchial chronic inflammation, inhaled corticosteroids and bronchodilators can make a significant improvement in the efficacy and prognosis. However, there are a small number of patients who are still difficult to control their condition by inhalation alone and need systemic medication. This prompted one to envisage that the lesion may involve small airways and lung tissue that are inaccessible to inhaled drugs. Since 90 years