title: Allergen skin prick testing in early childhood: reproducibility and prediction of allergic symptoms into early adulthood.
abstract: OBJECTIVE
  To assess the predictive value of skin prick testing in early childhood on subsequent allergic symptoms up to adult age.
  
  
  METHODS
  A cohort of 200 unselected healthy newborns was prospectively followed from birth to 20 years of age. Of them, 163 (82%) were reassessed at age 5 years, 150 (76%) at age 11 years, and 164 (83%) at age 20 years with a skin prick test that included 11 common allergens. On the basis of clinical examination and structured interview, the occurrence of atopic dermatitis, allergic rhinoconjunctivitis, recurrent wheezing, and symptoms of food hypersensitivity were recorded at each of the follow-up visits.
  
  
  RESULTS
  The reproducibility of skin prick test positivity at age 5 years was 100% at ages 11 and 20 years, ie, none of the skin prick-positive subjects turned negative during the follow-up. Gaining of new sensitizations to aeroallergens was common. Skin prick test positivity at age 5 years predicted allergic symptoms at ages 11 (sensitivity 28%, specificity 94%) and 20 years (sensitivity 23%, specificity 91%) but not atopic dermatitis.
  
  
  CONCLUSIONS
  Skin prick test positivity at age 5 years strongly predicts later skin prick test positivity and is associated with respiratory symptoms, ie, allergic rhinoconjunctivitis and recurrent wheezing, at ages 11 and 20 years. However, skin prick test negativity at age 5 years does not exclude sensitization and allergic symptoms at a later age.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland. Electronic address: maria.pesonen@ttl.fi.
authors.forename: Maria
authors.initials: M
authors.lastname: Pesonen
authors.affiliation: Hospital for Children and Adolescents, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Markku J T
authors.initials: MJ
authors.lastname: Kallio
authors.affiliation: Hospital for Children and Adolescents, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Martti A
authors.initials: MA
authors.lastname: Siimes
authors.affiliation: Department of Dermatology and Allergology, the Skin and Allergy Hospital, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Annamari
authors.initials: A
authors.lastname: Ranki
mesh_terms: D000367:Age Factors; D000485:Allergens; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis*; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012882:Skin Tests / Q000379:methods; D055815:Young Adult
chemical_list: D000485:Allergens