title: Patterns of sensitization to food and aeroallergens in the first 3 years of life.
abstract: BACKGROUND
  There is a paucity of longitudinal studies of allergen sensitization in childhood.
  
  
  OBJECTIVE
  To investigate the pattern of sensitization in early childhood.
  
  
  METHODS
  A nested cohort of children (n = 543) were followed up from birth and given a skin prick test (SPT) at 1, 2, and 3 years of age. A detailed clinical history was obtained.
  
  
  RESULTS
  The prevalences of sensitization to aeroallergens were 1.3%, 6.4%, and 10.7% at 1, 2, and 3 years of age. The figures for food allergens were 2.8%, 3.9%, and 3.7%. There was a statistically significant increase in the prevalence of sensitization to >or=1 allergen between years 1 and 2 (P < .001) and years 2 and 3 (P = .032). Among those with a positive SPT at 1 year, 29% tested positive to additional allergens at 2 years (P = .0054). Sensitization to milk or egg at 1 year was a predictor for increased sensitization to peanut at 3 years (odds ratio, 34.8; P < .0001). Sensitization to egg at 1 year was associated with increased sensitization to aeroallergens at 3 years (odds ratios, house dust mite, 27.1, P < .001; cat, 8.9, P < .01; grass, 11.8, P = .005). For peanut and cat allergens, wheal size increases with the age of the child (P = .009 and P = .017, respectively).
  
  
  CONCLUSIONS
  Sensitization to allergens as demonstrated by positive SPT tends to increase with age, and this change can be detected in the first 3 years of life.
  
  
  CONCLUSIONS
  The high predictive value for early sensitization and a linear increase in SPT reactivity provide an opportunity for early intervention.
authors.affiliation: David Hide Asthma and Allergy Research Center, St Mary's Hospital, Newport, Isle of Wight, UK. tara.dean@port.ac.uk
authors.forename: Taraneh
authors.initials: T
authors.lastname: Dean
authors.forename: Carina
authors.initials: C
authors.lastname: Venter
authors.forename: Brett
authors.initials: B
authors.lastname: Pereira
authors.forename: S Hasan
authors.initials: SH
authors.lastname: Arshad
authors.forename: Jane
authors.initials: J
authors.lastname: Grundy
authors.forename: C Bernie
authors.initials: CB
authors.lastname: Clayton
authors.forename: Bernie
authors.initials: B
authors.lastname: Higgins
mesh_terms: D000388:Air; D000485:Allergens / Q000276:immunology*; D000818:Animals; D002415:Cats; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004391:Dust / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology*; D007223:Infant; D008297:Male; D015995:Prevalence; D012882:Skin Tests