title: Association between varicella zoster virus infection and atopic dermatitis in early and late childhood: a case-control study.
abstract: BACKGROUND
  Wild-type varicella zoster virus infection (WTVZV) early in childhood has been shown to protect against the development of asthma and atopy.
  
  
  OBJECTIVE
  To determine whether WTVZV in childhood protects against atopic dermatitis (AD).
  
  
  METHODS
  This retrospective, practice-based, case-control study randomly sampled 256 children and adolescents (age 1-18 years) with AD and 422 age-matched healthy controls from 2005 to 2007. Observations were made before the a priori hypothesis.
  
  
  RESULTS
  (1) A single episode of WTVZV in childhood is associated with decreased odds ratio (OR) of developing AD (conditional logistic regression; OR, 0.55; 95% CI, 0.34-0.89; P = .01). (2) When using intervals for age corresponding to bimodal distribution of age of WTVZV infection, the effects of WTVZV infection are significant when occurring at age 0 to 8 years (OR, 0.56; 95% CI, 0.35-0.90; P = .02), but not at 8 to 18 years (OR, 0.50; 95% CI, 0.19-1.31; P = .16). Considering 5-year intervals has similar findings. (3) WTVZV is associated with decreased odds of moderate AD (multinomial logistic regression; OR, 0.08, 95% CI, 0.04-0.15; P < .0001) or severe AD (OR, 0.04; 95% CI, 0.01-0.13; P < .0001). (4) WTVZV in children is associated with prolonged AD-free survival (Kaplan-Meier; median, 15.3 years; 95% CI, 10.9-18.0) compared with controls (median, 7.5 years; 95% CI, 4.8-11.9; log-rank test, P < .0001). (5) Children with WTVZV, compared with vaccine, who eventually develop AD require fewer pediatrician sick visits for management of AD (logistic regression; OR, 0.17; 95% CI, 0.06-0.51; P = .001).
  
  
  CONCLUSIONS
  WTVZV in childhood protects up to 10 years of age against AD, delays onset of AD symptoms, and decreases AD severity and office visits.
authors.affiliation: Department of Medicine, State University of New York Downstate, State University of New York Downstate Medical Center, Brooklyn, NY, USA. JonathanISilverberg@Gmail.com
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Silverberg
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Norowitz
authors.forename: Edward
authors.initials: E
authors.lastname: Kleiman
authors.forename: Nanette B
authors.initials: NB
authors.lastname: Silverberg
authors.forename: Helen G
authors.initials: HG
authors.lastname: Durkin
authors.forename: Rauno
authors.initials: R
authors.lastname: Joks
authors.forename: Tamar A
authors.initials: TA
authors.lastname: Smith-Norowitz
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002644:Chickenpox / Q000401:mortality / Q000821:virology; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000209:etiology / Q000401:mortality / Q000628:therapy / Q000821:virology; D005260:Female; D014645:Herpesvirus 3, Human; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D013997:Time Factors