Etiological Factors of Chronic Cough in Children of Mianyang Area

Abstract

Objective To investigate the etiological factors of nonspecific chronic cough in children of Mianyang area. Methods From January to December 2010, a total of 1 842 outpatient cases were diagnosed as nonspecific chronic cough in Central Hospital of Mianyang. They were divided into 3 groups according to different age-periods, infant group (n=998, between the age of 3 month-old to 3 years) , preschool group (n=416, between the age of 3 to 6 years old) , school and later group (n=428, between the age of 6-14 years old) . There had no significant differences between three groups on gender and course of disease (P>0.05) . The study protocol was approved by the Ethical Review Board of Investigation in Central Hospital of Mianyang. Informed consent was obtained from all participates' parents. All of the patients were first asked in detail about the history, complete physical examination, and the next step of auxiliary examination were conducted according to the medical history and physical examination results. The follow-up was conducted by telephone and clinic service for 3 months. Results Among those 1 842 cases, the etiological factors of 1 806 cases (98.05% ) were clear. The causes leading to nonspecific chronic cough were different in different age groups. There had significant differences on etiological factors among three groups (P<0.05) . The top two causes of nonspecific chronic cough of infant group were cough after infection (38.28%, 382/ 998) , cough variant asthma (36.97%,369/ 998) . While the main cause of the preschool group and school and later group were variant asthma [accounted for 62.26% (259/ 416) and 50.93% (218/ 428) , respectively) . Cough after infection ranked the second and accounted for 15.87% (66/ 416) in preschool group, upper airway cough syndrome ranked the second and accounted for 25.47% (109/ 428) in school and later group. Conclusions The etiological factors of nonspecific chronic cough in children of Mianyang area are complex. It may cause by single factor or multiple factors. Children in different age periods with nonspecific chronic cough have the different etiological factors. Key words: Chronic cough; Causes constituent; Child