The Causes And Clinical Features Of Chronic Cough In School-age Children

Objective1. To explore the diagnostic value of chronic features in common causes of chroniccough by analyzing common causes and chronic characteristics of school-age children withchronic cough..2.To learn airway hyperresponsiveness, induced sputum eosinophils and otherauxiliary check in the characteristics of different etiology of chronic cough in children anddiagnostic value of the chronicMethodsThe outpatients in Children’s Hospital Affiliated to Soochow University from March2012to December2013newly diagnosed with chronic cough who cough>4weeks, haveno obvious signs of lung and no abnormal chest radiograph are enrolled in this study. Thepatients are carefully inquiried now history, past history, family history, personal history,previous treatment and accept systematic physical examination.And the patients stop usinginflammatory drugs two weeks, while did the sputum EOS count, pulmonary function,airway provocation test (BPT), skin allergy testing (SPT) and24hours esophageal PHmeasurement.And to evaluate the cough symptom score and visual analog integrator(VAS),so that getting the preliminary diagnosis and giving appropriate treatment topatients. After two week of follow-up efficacy assessment,four weeks after the inducedsputum cell counts, pulmonary function, airway challenge test are done again and the finalstudy are defined combing with clinical efficacy.ResultsThe118children with chronic cough，who were prospective analyzed，aged6to14years old, The duration of chronic cough ranged4weeks to6years. Cause of chroniccough consisting of: Single cause: Upper Airway Cough Syndrome (UACS) was37cases, Cough Variant Asthma (CVA) was17cases,Past Infection Cough (PIC) was12cases,Gastroesophageal Reflux Cough (GERC) was2cases,Tourette (Tic) was3cases.Double causes: CVA+UACS in37cases, Tic+UACS in3cases, GERC+UACSin3cases，Eosinophilic Bronchitis (EB)+UACS in2cases.Three kinds and above:CVA+UACS+GERC in2cases. The duration of chronic cough were: CVA was (20.1±22.9) months, CVA+UACS was (18.6±18.2) months, UACS was (7.9±9.8) months, PICwas (1.5±0.6) months, Tic was（27.0±19.7）months,GERC was（42.0±25.5）months.CVA and CVA+UACS had no significant difference, but the two groups were significantlyhigher than that of UACS and PIC (P<0.05).UACS group was higher than that of PIC(P<0.05).The rate of dry cough in children with CVA was82.4%.The sensitivity diagnose ofdry cough to CVA was82.4%, the specificity was48.0%, the positive predictive valuewas61.3%, the negative predictive value was73.2%. The rate of wet cough in childrenwith with UACS was54.1%(20/37). The sensitivity diagnose of wet cough to UACS was54.1%, the specificity was78.6%, the positive predictive value was71.7%, the negativepredictive value was63.1%. To rate of night cough to CVA was64.7%(11/14), thesensitivity was64.7%, the specificity was85.4%, the positive predictive value was81.5%,the negative predictive value was70.7%.The rate of early morning cough to UACS was70.3%, the specificity was48.1%, the positive predictive value was57.5%, the negativepredictive value was61.8%. The rate of dry cough in children with PIC was82.4%, nocough specific time, infection significantly, the sensitivity diagnosis of PIC was83.3%, thespecificity was83.3%, positive predictive value was83.3%, negative predictive value was83.3%.The positive rate of UACS was35.1%with BPT.And PIC-positive rate was75%.Sputum EOS%, blood EOS%in CVA and CVA+UACS were significantly higher thanUACS, PIC, and the difference was statistically significant (P <0.05).The value of PD20indifferent etiology group: CVA was (0.5±0.25) mg, CVA+UACS was (0.6±0.3) mg,UACS was (1.8±0.6) mg, PIC was (1.6±0.8) mg. There was no significant differencebetween CVA group and CVA+UACS group in the value of PD20(P>0.05). The valueof PD20in UACS group was higher than PIC group, the difference was statisticallysignificant (P<0.05). The EOS proportion of induced sputum of four groups: the difference between CVA group (10±8.0)%and CVA+UACS group (12.7±14.6)%was notstatistically significant (P>0.05). But both were significantly higher than UACS group (1.8±0.6)%and PIC group (0.6±0.7)%, the difference was statistically significant (P <0.05).The positive rate of24h esophageal PH promting reflux was33.3%, the final diagnosisGERC positive rate was8.4%.The Cough scores and VAS scores between the two groupswas not statistically significant (P>0.05). Correlation analysis showed that, PD20-FEV1and cough symptoms total score had negative correlation (r=-0.497, P <0.001).The comparison of induced sputum before and after treatment: The EOS of sputum inCVA group and CVA+UACS group were significantly decreased after treatment, thedifference was significant (P<0.05), while the EOS of sputum in UACS group and PICgroup before and after treatment, the difference was not statistically significant (P>0.05).The comparison of PD20-FEV1before and after treatment: The difference of PD20-FEV1between CVA group and CVA+UACS group before and after the treatment was notstatistically significant (P>0.05), while the PD20-FEV1of UACS and PIC group aftertreatment were increased to varying degrees, and there was a significant differencecompared with before treatment (P<0.01).The cough scores and VAS scores weresignificantly improved after treatment,the differences were statistically significant (P<0.01).Conclusion1. The single cause of chronic cough in School-age children were UACS, CVA+UACS, and CVA and the double causes of CVA+UACS were most common, accountingone-third of the total. The GERC and EB are relatively rare to adult.2. The cough features of CVA are dry cough and cough at night. AND theexercise-induced cough in diagnosis of CVA is highly sensitive. The cough phase ofUACS is mainly in the morning and at bedtime and the Pharyngeal positive signs havesuggestive effect on UACS. The Cough nature and phase of PIC patients have nosignificant specificity, but the role of infection-related to PIC is greater.3. The airway inflammation of CVA is eosinophilic inflammation and AHR is a basicfeature of CVA. Sputum EOS decreased significantly after treatment. However, AHR hadno significant improvement.The UACS and PIC are non-eosinophilic inflammation. AHRaccouts for certain proportion in them. No significant change found in sputum EOS, but AHR improved significantly.4. The cough symptom score assessment have no significantly difference in differentcauses of chronic cough. But cough symptom score are related to airwayhyperresponsiveness to some extent.