临床上通常将以咳嗽为唯一症状或主要症状、时间超过 8周、胸部x检查无明显异常者称为不明原因慢性咳嗽，简称慢性咳嗽 。慢性咳嗽是内科门诊患者最常见的病症，与典型支气管哮喘、肺部感染、肺纤维化和支气管肺癌等疾病不同，由于缺乏典型的相关症状，胸片检查无异常，一些临床医生习惯性地给病人戴上“支气管炎或慢性支气管炎”(简称“慢支”)的帽子，给予止咳祛痰或反复使用多种抗生素治疗，当然临床疗效并不理想。我们进行的流行病学调查结果显示，72％的慢性咳嗽患者被诊断为“支气管炎、慢支或慢性咽喉炎”，而病因诊断显示其中慢性支气管炎仅占4％(该资料尚未发表)。 慢性咳嗽的病因非常复杂，但并非毫无规律可循。只要掌握正确的诊断方法，按照慢性咳嗽病因诊断程序，大部分患者实际上可以获得明确的病因诊断，根据病因进行特异性治疗能够取得良好的治疗效果。在诊断慢性咳嗽时主要应注意以下几个问题。
胃食管反流(GER)是指胃酸和其他胃内容物反流进入食管，正常人存在一定程度的反流，称为生理性反流。GER 可以引起临床症状，甚至组织病理学的改变。当出现胃烧灼、反酸、胸骨后疼痛等临床症状和(或)组织病理学的改变时，也被称为胃食管反流病(GERD)。以慢性咳嗽为主要临床表现的GERD称为胃食管反流性咳嗽(GERC)。2006年蒙特利尔会议提出了反流性咳嗽综合征的定义 。GERC 是慢性咳嗽的常见原因，发生率为5％~41％ ，存在一定的地区差异。欧美报道极为常见，而日本极为少见，国内 GERC占慢性咳嗽病因的12％。
Gibson等首先发现7例慢性咳嗽患者表现为慢性刺激性干咳或咳少许黏痰，诱导痰嗜酸粒细胞增高，糖皮质激素治疗效果良好；但患者肺通气功能正常，无气道高反应性 (AHR)，峰流速(PEF)变异率正常，无法诊断为支气管哮喘，因而称之为嗜酸粒细胞性支气管炎(EB)。研究结果发表于 1989年国际著名杂志柳叶刀(Lancet)。从Gibson等提出 EB的诊断以来，受到国内外广大专家的重视，虽然目前对 EB是否是一种独立的疾病或哮喘的早期阶段尚存在一些争议，但愈来愈多的证据表明EB是一种独立的疾病 。下面从EB的定义、病因、病理免疫特征、临床表现、治疗反应及预后等方面对此问题进行讨论，说明EB是一种独立的疾病。
Objective Chronic cough is often present as increasing cough reaction to various physical and chemical stimulating factors. This study is aimed to investigate the difference of cough sensitivity and its mechanisms which are not clear among different causes of chronic cough. Methods Patients with chronic cough were recruited from cough clinic of Guangzhou Institute of Respiratory Diseases between 2005 to 2010. Using a modified diagnostic algorithm of chronic cough, common causes were identified. Capsaicin cough provocation test was also performed in these patients to assess the cough threshold. The relations between cough reflex sensitivity and duration of cough, cough severity, pulmonary function, induced sputum cell counts were then investigated. Results Through the diagnostic algorithm of chronic cough, the current study evaluated 133 adult patients, including 24 cases with upper airway cough syndrome (UACS) , 26 patients with cough variant asthma (CVA) , 31 cases with eosinophilic bronchitis (EB) , 30 patients with atopic cough (AC) , 22 cases with gastroesophageal reflux induced cough (GERC) . There were 30 healthy volunteers recruited as normal control. The cough threshold of LgC5 in AC, CVA, EB, GERC and UACS was 1.70 ±0.70, 2.12 ±0.67, 2.13 ±0.69, 1.69 ±0.73, 2.16 ±0.66, respectively. The LgC5 of the normal group ( 2.63 ±0.39) was higher than those in chronic cough groups( All P lt; 0.05) . The LgC5 of AC and GERC were lower than CVA, EB and UACS ( all Plt;0.05) . Duration and daytime score of cough showed positive correlations with LgC5( r =-0. 280, -0. 168, all P lt;0.05) . Pulmonary function and differential cell count of induced sputumwere not associated with LgC5 ( all Pgt;0.05) . Conclusions Different cause of chronic cough exhbit high cough reflex sensitivity to different extent. The difference of cough sensitivity may reflect the different pathogenesis among different causes, and may be related to the type of nerve fiber dominating the cough reflex.
Objective To investigate the etiological diagnosis of chronic cough with pharyngitis-like manifestations. Methods Patients with chronic cough and pharyngitis-like manifestations were recruited from Outpatient Department of Guangzhou Institute of Respiratory Diseases between December 2002 to March 2010. The causes of chronic cough were investigated using a well-established diagnostic protocol, including history taking and physical examination, pulmonary function tests, induced sputum cytology, 24-h esophageal pH monitoring, etc. The final diagnosis depended on clinical manifestations, examination findings, and a successful response to therapy. Results 326 patients with chronic cough and pharyngitislike manifestations were included in the study with amedian duration of 24 ( 2 ～480) months, amean age of 41 ±13 years. The causes of chronic cough were identified as follows: post nasal drip syndrome or upper airway cough syndrome in 73 cases ( 23. 31% ) , cough variant asthma in 61 cases( 18. 71% ) , eosinophilic bronchitis in 70 cases( 22. 47% ) , gastroesophageal reflux-induced cough in 54 cases ( 16. 56% ) , atopiccough in 48 cases ( 14. 72% ) , and others in 40 cases ( 12. 27% ) . There is no significant difference in percentage of common causes of chronic cough ( P gt; 0. 05) . Conclusion The proportions of upper airway syndrome and other common causes are similar in chronic cough with pharyngitis-like manifestatioins, whichsuggest pharyngitis-like manifestations are not specific for diagnosis of upper airway cough syndrome.
ObjectiveTo explore the spectrum and frequency of respiratory symptoms in outpatients clinics.MethodsPatients were enrolled from outpatient clinic of Guangzhou Institute of Respiratory Disease. Information about respiratory symptoms especially cough was obtained from the survey questionnaire from July 2013 to August 2013 .ResultsA total of 900 were eligible out of 939 questionnaires. The mean age of the patients was (48.9±18.3) years, 453 (50.3%) were males, 447 (49.7%) were females. The cases of cough, wheeze, polypnea, chest distress, pharyngalgia, catarrh, chest pain, throat itching, fever, hemoptysis and other symptom was 687 (76.3%), 310 (34.4%), 307 (34.1%), 173 (19.2%), 107 (11.9%), 101 (11.2%), 82 (9.1%), 59 (6.6%), 36 (4.0%), 10 (1.1%) and 129 (14.3%) out of the patients, respectively. In patients with cough, 69.5% of them considered cough as their predominant symptom, and 22.1% of them reported that cough was the only symptom. 56.3% of cases were chronic cough, while acute and subacute cough accounted for 29.7% and 14.0%, separately. The proportion of female in acute cough was significantly higher than that of males (60.3%vs. 39.7%, P<0.01).ConclusionsCough, especially the chronic cough is the most common reason for patients who seeking health care in outpatient clinic of respirologist. There are more females suffered from acute cough than males.