The Spectrum And Clinical Features Of Causes For Chronic Cough In Shenyang And The Surrounding Areas

IntroductionMultiple studies have shown that in approximately 95 percent of cases in immunocompetent patients, chronic cough results from postnasal drip syndrome from conditions of the nose and sinuses, asthma, gastroesophageal reflux disease, chronic bronchitis due to cigarette smoking or other irritants, bronchiectasis, eosinophilic bronchitis, or the use of an angiotensin-converting-enzyme inhibitor. Melvin R. Pratter made three of their common cause, that upper airway cough syndrome, cough variant asthma and gastroesophageal reflux disease . China in recent years carried out a preliminary diagnosis and treatment of cough related to clinical research, and in 2005, China enacted the "coughing diagnosis and treatment guidelines (draft)".To further define the etiology of chronic cough and clinical features of various causes, this study follows the diagnosis of chronic cough flow, collected clinic patients with chronic cough in the Department of Respiratory Medicine, First Affiliated Hospital of China Medical University and took comparative analysis with the results of several domestic hospitals, provided the basis for empirical treatment of chronic cough in Shenyang and the surrounding areas.Subjects and methods1,subjectsCollected the clinical data of patients with chronic cough from December 2008 to March 2010 of the First Affiliated Hospital of China Medical University. Inclusion criteria:(1) cough time≥8 weeks; (2) conventional chest X-ray examination showed no abnormal; (3) subjects aged≥15 years of age, gender and race open; (4) the subjects were non-smoking patients. 2,methodsAccording to the "coughing diagnosis and treatment guidelines (draft)" diagnostic procedures. Follow the following principles:(1) a comprehensive history taking, including ear, nose throat and digestive system disease history; (2) Select the check according to history, from simple to complex; (3) to investigate common and rare diseases after the check; (4) diagnosis and treatment of both simultaneously or in sequence. If the former condition does not have the time, according to the clinical characteristics of diagnostic treatment, and response to treatment to determine cough under treatment fails and then select the check. Specific methods:(1) careful history taking and physical examination; (2) chest radiograph; (3) pulmonary function+ methacholine bronchial provocation test; (4) in induced sputum cytology; (5) peripheral blood eosinophil counts, allergen skin test, serum total IgE and specific IgE screening; (6) According to a preliminary diagnosis of the above information, and to cause treatment; (7) If still can not diagnose, or initial treatment ineffective, following selective examination, including sinus X ray or CT examination, esophageal 24hpH value determination, bronchoscopy, and nasopharyngeal endoscopy and so on; (8) According to test results and response to treatment to establish the cause diagnosis.3,Diagnostic criteriaCough variant asthma (CVA), rhinitis and/or sinusitis (R/S), gastroesophageal reflux-related chronic cough (GERC), eosinophilic bronchitis (EB), atopic cough (AC), post-infectious cough (PIC), follow the "Diagnosis and treatment of cough Guide line(draft)" and Diagnosis and treatment of cough guideline(2009 Edition).4,Statistical analysisUsing Descriptive statistical analysis software application SPSS13.0 and using (?)±s exemplifies measurement data. Using the percentage of one kind of causes accounting for the total number of causes as the distribution of causes, and the total number of causes is the sum of single causes and complex causes. The results were compared with those of Guangzhou and Beijing, and using x2 test. Results1. Constitute of causes for chronic coughThe cause of chronic cough was defined in 98.1%(102/104) of the patients. The most important causes of cough were:cough variant asthma (CVA) (n=41,39.4%), rhinitis and/or sinusitis (n=14,13.5%), eosinophilic bronchitis (EB) (n=13,12.5%), atopic cough (AC) (n=12,11.5%), post-infectious cough (PIC) (n=12,11.5%). The percentage of CVA, PIC was significantly higher than those reported in Guangzhou (x2value was 28.05 and 4.99, P<0.01 and P<0.05); Compared with those from China-Japan Friendship hospital, the percentage of AC, EB and PIC was significantly higher(x2value was 5.91,4.27 and 14.98, P<0.05, P<0.05 and P<0.01 respectively).2. The clinical features of different causes for chronic coughThere was more nocturnal cough in CVA (70.7%,29/41) than in other causes (x2=3.64, P>0.05). CVA patients with rhinitis was 17.1%(7/41), CVA seasonal increase by 34.1%(14/41), more common in winter, accounting for 78.6%(11/14), which were different from those reported in China-Japan Friendship Hospital, and there was more productive cough in rhinitis and/or sinusitis (64.3%(9/14),x2=2.06, P>0.05), there was no significant difference between rhinitis/sinusitis and other causes (x2= 2.06, P> 0.05), which was also different from those reported in China-Japan Friendship Hospital (x2=24.99, P<0.01).Conclusions1. The top 5 causes of chronic cough were CVA, rhinitis and/or sinusitis, EB, AC, and PIC.2. After the combined analysis of this survey and the results from Guangzhou 2003-2004, diagnosed cases of CVA, EB, rhinitis and/or sinusitis, AC and GERC accounted for 77.7% of cough. This suggests that these five kinds of diseases as the main cause of chronic cough, to strengthen the diagnosis and treatment of these diseases research is the key to diagnosis and treatment of chronic cough.3. The morbidity of PIC in this survey was significantly higher than that of Guangzhou and Beijing, may due to the cold weather of Northeast region of China, high morbidity of flu and other respiratory tract infections, airway by the cold and the role of respiratory viruses and other pathogens, repeated spasm and inflammatory stimulation, making infections difficult to control, leading to chronic cough.4. Epidemiological study found the incidence of chronic cough caused by GER was 5%-41%, and European and American studies show that GERD accounts for a larger proportion of chronic cough, as much as 20%-41%. In China, some studies showed that, GERC accounting for 11.8% of patients with chronic cough. In this study, GERC ratio of 1.9% reported GERC closer to the proportion of Japan (0.5%).5. Rhinitis is not only the common cause of chronic cough, but also closely related with CVA. In this survey productive cough in CVA is 53.7% which is so high possibly because it is often associated with rhinitis caused by nasal secretions flow into the throat and mouth, as well as cold weather in Northeast, repeated airway spasm and inflammation caused by stimulating more Secretions.