“不明原因”慢性咳嗽的病因构成和临床特征分析

The spectrum and clinical features of causes for chronic cough

目的分析经遵循我国慢性咳嗽诊断流程明确的慢性咳嗽患者的病因构成和临床特征，为经验性诊治慢性咳嗽提供依据。方法对“不明原因”慢性咳嗽患者，遵循我国咳嗽指南慢性咳嗽诊断流程，在询问病史和查体的基础上，进行常规肺通气功能测定和支气管激发试验、诱导痰细胞学检查、鼻窦X线片或CT、24h食管pH值监测等检查，根据检查结果和治疗后反应，最后确定病因诊断。收集卫生部中日友好医院患者病因资料并与广州呼吸疾病研究所的研究结果进行比较，以√检验比较构成比差异。结果2005年10月至2009年2月共收集不明原因慢性咳嗽患者103例，明确诊断咳嗽病因123例次。慢性咳嗽病因分布依次为咳嗽变异性哮喘41例次（33．3％），鼻炎／鼻窦炎30例次（24．4％），胃食管反流性咳嗽25例次（20．3％），药物性咳嗽7例次（5．7％），嗜酸粒细胞性支气管炎6例次（4．9％），变应性咳嗽4例次（3．3％），肺间质纤维化2例次（1．6％），左心功能不全和支气管扩张各1例次（0．8％），病因未明6例次（4．9％）。单一病因咳嗽者86例（83．5％），二重病因14例（13．6％）、三重病因3例（2．9％）。咳嗽变异性哮喘患者夜间咳嗽发生率最高[80．9％（36／41），χ^2=19．81，P〈0．01]，63．4％（26／41）合并鼻炎，68．3％（28／41）有季节性加重，其中67．8％（19／28）于秋季加重；胃食管反流性咳嗽以日间咳嗽为主，56．0％（14／25）有进食相关性咳嗽，68．0％（17／25）伴有反流相关症状；鼻炎／鼻窦炎患者有痰咳嗽发生率最高[73．3％（22／30），χ^2=24．99，P〈0．01]。与广州资料相比，咳嗽变异性哮喘和胃食管反流性咳嗽比例高于广州（χ^2值分别为9．52和4．56，均P〈0．01），而嗜酸粒细胞性支气管炎和变应性咳嗽比例低于广州（χ^2值分别为17．61和7．86，均P〈0．01）。结论慢性咳嗽常见病因构成为咳嗽变异性哮喘、鼻炎／鼻窦炎、胃食管反流性咳嗽、药物性咳嗽、嗜酸粒细胞性支气管炎和变应性咳嗽，与广州资料比较具有一定的差异。各种病因的咳嗽具有一定的临床特征，慢性咳嗽的病因构成和临床特征可为经验性诊治慢性咳嗽提供依据。

Objective To explore the spectrum and clinical features of causes for chronic cough. Methods A total of 103 patients with at least 8 weeks of chronic cough and normal chest radiographs were recruited from the outpatient clinic of China-Japan Friendship Hospital Department of Respiratory Diseases between Oct 2005 to Feb 2009. The causes were investigated using a well established protocol according to The Chinese Respiratory Society guidelines for management of cough. The diagnostic protocol included history inquiring and physical examination, pulmonary function tests, induced sputum cell differentials, 24 h esophageal pH monitoring, CT of the paranasal sinuses or chest, fiberoplic rhinoscopy or bronchoscopy. The final diagnosis was made based on clinical manifestations, examination findings and a positive response to therapy. The results were compared with those reported in Guangzhou before. Results The cause of chronic cough was defined in 95.1% of the patients, of which 83 patients （83.5%） with a single cause, 32 （13.6%） with 2 causes, and 3 （2. 9% ） with 3 causes. The most important causes of cough were： cough variant asthma （CVA） （ n = 41,33.3% ） , rhinitis and/or sinusitis （ n = 30, 24.4% ） , gastroesophageal reflux （GERC） （ n = 25, 20. 3% ）, medicine related （ n = 7, 5.7% ）, eosinophilic bronchitis（EB） （ n = 6, 4. 9% ）, atopic （ n = 4, 3.3% ） , and idiopathic （ n = 6, 4.9% ）. Other causes included pulmonary interstitial fibrosis （ n = 2, 1.6% ） , left heart insufficiency （ n = 1, 0. 8% ） and bronchiectasis （n = 1, 0. 8% ） . There was more nocturnal cough in CVA （80. 9% , 36/41 ） than in other causes （χ^2 = 19. 81 ,P 〈0. 01 ）. In CVA, 63.4% （26/41） was complicated with atopic rhinitis, 68.3% （28/41） showed seasonal variations, and 67.8% （19/28） aggravated in the autumn. GERC manifested more day coughs, with 56. 0% （ 14/25 ） cough associated with taking food and 68.0% （ 17/25 ） with reflux symptoms. There was more productive cough in rhinitis and/or sinusitis （73.3 % （22/30）,χ^2 = 24. 99,P 〈 0. 01 ）. The percentages of CVA and GERC were significantly higher than those reported in Guangzhou （χ^2 value were 9. 52 and 4. 56 respectively, P 〈 0. 01 ）, but those of EB and atopic cough were significantly lower （p values were 17. 61 and 7.86 respectively,P 〈0. 01 ）. Conclusions The most common causes of chronic cough in our study were CVA, rhinitis and/or sinusitis, GERC, medicine related cough, EB and atopic cough, which were different from previous reports in other cities such as Guangzhou. The spectrum and clinical features of causes for chronic cough are important in the diagnostic procedure of chronic cough.