title: Positive nickel patch tests in infants are of low clinical relevance and rarely reproducible.
abstract: BACKGROUND
  We have previously reported patch test reactivity to nickel sulphate in a cohort of unselected infants tested repeatedly at 3-18 months of age. A reproducible positive reaction at 12 and 18 months was selected as a sign of nickel sensitivity provided a patch test with an empty Finn chamber was negative. A reproducible positive reaction was seen in 8.6% of the infants. The objective of this study is to follow-up on infants with alleged nickel sensitivity.
  
  
  METHODS
  A total of 562 infants were included in the cohort and patch tested with nickel sulphate (ICDRG guidelines). The 26 children with a positive patch test reaction to nickel sulphate at 12 and 18 months were offered repeated patch tests at 3 and 6 yr.
  
  
  RESULTS
  Among the 21 children tested at both 12 months, 18 months and at 3 and 6 yr only 2 of 21 had reproducible nickel reactions (one clinically relevant), 13 of 21 were negative and 6 of 21 were negative at 3 or 6 yr.
  
  
  CONCLUSIONS
  Only 9.5% of the children had reproducible nickel sulphate reactivity, while 62% became negative. The results are noteworthy and can be interpreted in different ways: Repeated nickel patch tests did not cause patch test sensitization. The test reactions in infancy are probably of irritant or non-specific nature. Hence, nickel patch tests should only be performed in small children if there is a clinical suspicion of nickel-induced allergic contact dermatitis.
authors: Department of Dermatology and Allergy Centre, Odense University Hospital, University of Southern Denmark, Odense C, Denmark. Charlotte.moertz@ouh.regionsyddanmark.dk
authors: Charlotte G
authors: CG
authors: Mortz
authors: Henrik F
authors: HF
authors: Kjaer
authors: Esben
authors: E
authors: Eller
authors: Morten
authors: M
authors: Osterballe
authors: Lene A
authors: LA
authors: Norberg
authors: Arne
authors: A
authors: Høst
authors: Carsten
authors: C
authors: Bindslev-Jensen
authors: Klaus E
authors: KE
authors: Andersen
mesh_terms: D000485:Allergens / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009532:Nickel / Q000008:administration & dosage / Q000009:adverse effects; D010328:Patch Tests / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D000485:Allergens; C029938:nickel sulfate; D009532:Nickel