Desai Dhan, Brightling Chris
Department of Infection, Inflammation, and Immunity, University of Leicester, Institute for Lung Health, Glenfield Hospital, UK.
Otolaryngol Clin North Am. 2010 Feb;43(1):123-30, x. doi: 10.1016/j.otc.2009.11.006.
Among the most common causes of chronic cough are asthma (25%) and nonasthmatic eosinophilic bronchitis (10%). In asthma, cough may present as an isolated symptom, in which case it is known as cough variant asthma. Variable airflow obstruction and airway hyper-responsiveness are cardinal features of asthma, which are absent in nonasthmatic eosinophilic bronchitis. The presence of eosinophilic airway inflammation is a common feature of asthma and is a diagnostic criterion for nonasthmatic eosinophilic bronchitis. At a cellular level, mast cell infiltration into the airway smooth muscle bundle, narrowing of the airway wall, and increased interleukin-13 expression are features of asthma and not nonasthmatic eosinophilic bronchitis. In most cases, the trigger that causes the cough is uncertain, but occasionally occupational exposure to a sensitizer is identified, and avoidance is recommended. In both conditions, there is improvement following treatment with inhaled corticosteroids, which is associated with the presence of an airway eosinophilia and increased exhaled nitric oxide. Generally, response to therapy in both conditions is very good, and the limited long-term data available suggest that both usually have a benign course, although in some cases fixed airflow obstruction may occur.
慢性咳嗽最常见的病因包括哮喘（25%）和非哮喘性嗜酸性粒细胞性支气管炎（10%）。在哮喘中，咳嗽可能表现为孤立症状，在这种情况下被称为咳嗽变异性哮喘。气流受限和气道高反应性是哮喘的主要特征，而非哮喘性嗜酸性粒细胞性支气管炎不存在这些特征。嗜酸性粒细胞性气道炎症是哮喘的常见特征，也是非哮喘性嗜酸性粒细胞性支气管炎的诊断标准。在细胞水平上，肥大细胞浸润气道平滑肌束、气道壁狭窄以及白细胞介素 - 13表达增加是哮喘的特征，而非哮喘性嗜酸性粒细胞性支气管炎则没有这些特征。在大多数情况下，引发咳嗽的诱因尚不确定，但偶尔可确定职业性接触致敏原，此时建议避免接触。在这两种疾病中，吸入糖皮质激素治疗后病情都会改善，这与气道嗜酸性粒细胞增多和呼出一氧化氮增加有关。一般来说，这两种疾病对治疗的反应都非常好，现有的有限长期数据表明，尽管在某些情况下可能会出现固定性气流受限，但这两种疾病通常病程良性。
