title: Streptococcus pyogenes upper respiratory infection and atopic conditions other than asthma: a retrospective cohort study.
abstract: BACKGROUND
  Patients with asthma have an increased risk of Streptococcus pyogenes infection compared with those without asthma. It is unknown whether this is true for children with other atopic conditions such as atopic dermatitis or allergic rhinitis.
  
  
  OBJECTIVE
  To determine the risk of developing S. pyogenes infections of the upper respiratory tract in children and adolescents with atopic dermatitis and/or allergic rhinitis.
  
  
  METHODS
  We conducted a retrospective cohort study that followed a convenience sample of 340 healthy children. Atopic dermatitis or eczema and allergic rhinitis or hay fever were determined based on a physician diagnosis documented in medical records. All laboratory test results of cultures, rapid antigen detection, and polymerase chain reaction tests for S. pyogenes infections during the first 18 years of life were collected to compare the incidence of S. pyogenes infections between children with and without a physician diagnosis of atopic conditions. A Poisson regression was fit to determine the association between asthma and S. pyogenes infections, controlling for other covariates including asthma.
  
  
  RESULTS
  Of the 340 subjects, 327 were eligible for the study. Of these 327 subjects, 143 (44%) had atopic conditions other than asthma. The incidence of S. pyogenes infections in children with atopic conditions other than asthma and those without atopic conditions was 0.24 per person-year and 0.18 per person-year, respectively. The adjusted risk ratios for allergic rhinitis and atopic dermatitis were 1.36 (95% CI 1.07 to 1.66, p=0.011) and 1.30 (95% CI 0.98 to 1.71, p=0.06), respectively, controlling for asthma and other covariates.
  
  
  CONCLUSIONS
  In addition to asthma, allergic rhinitis but not atopic dermatitis is associated with an increased risk of S. pyogenes upper respiratory tract infections.
authors.affiliation: Department of Community Pediatric & Adolescent Medicine, Mayo Clinic, Rochester, Minnesota 55944, USA. juhn.young@mayo.edu
authors.forename: Young J
authors.initials: YJ
authors.lastname: Juhn
authors.forename: Diana
authors.initials: D
authors.lastname: Frey
authors.forename: Xujian
authors.initials: X
authors.lastname: Li
authors.forename: Robert
authors.initials: R
authors.lastname: Jacobson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000150:complications / Q000382:microbiology; D004485:Eczema / Q000150:complications / Q000382:microbiology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications* / Q000382:microbiology; D008297:Male; D016012:Poisson Distribution; D012141:Respiratory Tract Infections / Q000209:etiology* / Q000382:microbiology; D012189:Retrospective Studies; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000382:microbiology; D012307:Risk Factors; D013290:Streptococcal Infections / Q000209:etiology* / Q000382:microbiology; D013297:Streptococcus pyogenes