title: Clinical features of influenza A and B in children and association with myositis.
abstract: Influenza virus is among the most common causes of respiratory illness, which may manifest as a range of conditions, from mild upper respiratory tract infection to bronchiolitis and pneumonia. Acute childhood myositis associated with influenza occurs mostly in influenza B infection. In this retrospective study, we analyzed the characteristics of 197 children with influenza virus treated from January 2000 to December 2001. Among them, 73 children had influenza A infection and 124 had influenza B infection. Influenza A virus outbreaks occurred in January 2000, July 2001, and December 2001, while influenza B virus outbreaks occurred from March 2000 to May 2000 and from December 2000 to February 2001. The most common clinical manifestations of influenza A and influenza B virus infection included fever, cough, and rhinorrhea. These infections also frequently manifested as laryngo-tracheobronchitis, pneumonia, and unexplained fever, which led to hospitalization. The most common clinical diagnosis was upper respiratory tract infection. The rates of benign acute childhood myositis in influenza A and influenza B were 5.5% and 33.9%, respectively. Creatine kinase levels were elevated in most myositis cases and boys were more commonly affected. Acute childhood myositis was more commonly seen in influenza B infection.
authors.affiliation: Department of Pediatrics, Taiwan Adventist Hospital, Taipei, Taiwan, ROC.
authors.forename: Jen-Jan
authors.initials: JJ
authors.lastname: Hu
authors.forename: Chuan-Liang
authors.initials: CL
authors.lastname: Kao
authors.forename: Ping-Ing
authors.initials: PI
authors.lastname: Lee
authors.forename: Chung-Ming
authors.initials: CM
authors.lastname: Chen
authors.forename: Chin-Yun
authors.initials: CY
authors.lastname: Lee
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Lu
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Huang
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization; D006801:Humans; D009980:Influenza A virus; D009981:Influenza B virus; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology* / Q000821:virology; D008297:Male; D009220:Myositis / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors