title: Recurrent childhood upper respiratory tract infections do not reduce the risk of adult atopic disease.
abstract: BACKGROUND
  Children of large families and those attending day care are at increased risk of respiratory tract infections, which in turn may protect against the development of allergic disease. Longitudinal studies investigating these associations beyond childhood are, however, scarce.
  
  
  OBJECTIVE
  To investigate the association between childhood recurrent upper respiratory tract infections (URTI) and asthma, allergic rhinitis (AR) and eczema in adulthood.
  
  
  METHODS
  A birth cohort of 1055 members followed prospectively from the ages of 2 to 21 years. Detailed information on URTI between the ages of 2 and 4 years was collected at 3 monthly intervals in a standardized interview. At the age of 8 years, a parental questionnaire regarding URTI between the ages of 4 and 8 years was used. The incidence of asthma and atopic disease at the age of 21 years was determined using a standardized questionnaire.
  
  
  RESULTS
  Of the original cohort, 693 (66%) members completed the questionnaire. Children who experienced recurrent URTI before the age of 2 years, between the ages of 2-4 years and between ages of 4 and 8 years were not less likely to have asthma at 21 years of age than children who did not experience recurrent URTI, relative risk (RR) 0.97 (95% confidence interval (CI) 0.65-1.46), RR 1.45 (CI 0.95-2.21) and RR 1.51 (CI 0.97-2.36), respectively. Neither were recurrent URTI associated with a decreased risk of AR, nor eczema at the age of 21 years.
  
  
  CONCLUSIONS
  Recurrent URTI in childhood did not reduce the risk of atopic disease in young adulthood.
authors.affiliation: Department of Paediatric Respiratory Medicine, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht, The Netherlands. w.balemans@umcutrecht.nl
authors.forename: W A F
authors.initials: WA
authors.lastname: Balemans
authors.forename: M M
authors.initials: MM
authors.lastname: Rovers
authors.forename: A G M
authors.initials: AG
authors.lastname: Schilder
authors.forename: E A M
authors.initials: EA
authors.lastname: Sanders
authors.forename: J L L
authors.initials: JL
authors.lastname: Kimpen
authors.forename: G A
authors.initials: GA
authors.lastname: Zielhuis
authors.forename: C K
authors.initials: CK
authors.lastname: Ent
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000209:etiology / Q000276:immunology; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D016001:Confidence Intervals; D004485:Eczema / Q000209:etiology / Q000276:immunology; D005191:Family Characteristics; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology* / Q000276:immunology; D015994:Incidence; D008297:Male; D011446:Prospective Studies; D012008:Recurrence; D012141:Respiratory Tract Infections / Q000150:complications* / Q000276:immunology; D012306:Risk