title: Increased risk of herpes zoster in children with asthma: a population-based case-control study.
abstract: OBJECTIVE
  To determine the risk of herpes zoster (HZ) in children with and without asthma.
  
  
  METHODS
  This study was designed as a population-based case-control study. We examined all children (aged <18 years) with possible HZ in Olmsted County, Minnesota, between 1996 and 2001 (n = 306; identified by International Classification of Diseases, Eighth Revision codes and predetermined criteria for HZ) to identify true cases. To determine the association between asthma and HZ, we compared the frequency of asthma among children with HZ with that among age- and sex-matched corresponding controls (1:1 matching) who resided in Olmsted County, Minnesota, during the study period. Asthma was ascertained based on predetermined criteria. A conditional logistic regression model was used to calculate ORs and 95% CIs.
  
  
  RESULTS
  We identified 277 eligible patients with HZ, 63 (23%) of whom had a history of asthma before the index date of HZ, compared with 35 of 277 (12.6%) matched controls (aOR, 2.09; 95% CI, 1.24-3.52; P = .006), adjusting for varicella vaccination and atopy status. The population-attributable risk percentage was 12%. Controlling for asthma and atopy status, varicella vaccination was associated with reduced risk of HZ (aOR, 0.44; 95% CI, 0.21-0.92; P = .028).
  
  
  CONCLUSIONS
  Asthma may be an unrecognized risk factor for reactivation of a non-airway-related latent infection such as HZ in children.
authors.affiliation: Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Bong-Seong
authors.initials: BS
authors.lastname: Kim
authors.forename: Sonia
authors.initials: S
authors.lastname: Mehra
authors.forename: Barbara
authors.initials: B
authors.lastname: Yawn
authors.forename: Charles
authors.initials: C
authors.lastname: Grose
authors.forename: Robert
authors.initials: R
authors.lastname: Tarrell
authors.forename: Brian
authors.initials: B
authors.lastname: Lahr
authors.forename: Young J
authors.initials: YJ
authors.lastname: Juhn
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006562:Herpes Zoster / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors
keywords: HZ; Herpes zoster