title: Elicitation threshold of cobalt chloride: analysis of patch test dose-response studies.
abstract: BACKGROUND
  Cobalt is a strong skin sensitizer (grade 5 of 5 in the guinea-pig maximization test) that is used in various industrial and consumer applications. To prevent sensitization to cobalt and elicitation of allergic cobalt dermatitis, information about the elicitation threshold level of cobalt is important.
  
  
  OBJECTIVE
  To identify the dermatitis elicitation threshold levels in cobalt-allergic individuals.
  
  
  METHODS
  Published patch test dose-response studies were reviewed to determine the elicitation dose (ED) levels in dermatitis patients with a previous positive patch test reaction to cobalt. A logistic dose-response model was applied to data collected from the published literature to estimate ED values. The 95% confidence interval (CI) for the ratio of mean doses that can elicit a reaction in 10% (ED(10)) of a population was calculated with Fieller's method.
  
  
  RESULTS
  On the basis of five included studies, the ED10 values of aqueous cobalt chloride ranged between 0.0663 and 1.95 µg cobalt/cm(2), corresponding to 30.8-259 ppm.
  
  
  CONCLUSIONS
  Our analysis provides an overview of the doses of cobalt that are required to elicit allergic cobalt contactdermatitis in sensitized individuals, and thereby the basis for future prevention of cobalt allergy.
authors.affiliation: Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, DK-2900 Hellerup, Denmark.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Fischer
authors.affiliation: Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, DK-2900 Hellerup, Denmark.
authors.forename: Jeanne D
authors.initials: JD
authors.lastname: Johansen
authors.affiliation: Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, DK-2900 Hellerup, Denmark.
authors.forename: Aage
authors.initials: A
authors.lastname: Voelund
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
authors.forename: Carola
authors.initials: C
authors.lastname: Lidén
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
authors.forename: Anneli
authors.initials: A
authors.lastname: Julander
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
authors.forename: Klara
authors.initials: K
authors.lastname: Midander
authors.affiliation: Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, DK-2900 Hellerup, Denmark.
authors.forename: Torkil
authors.initials: T
authors.lastname: Menné
authors.affiliation: Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, DK-2900 Hellerup, Denmark.
authors.forename: Jacob P
authors.initials: JP
authors.lastname: Thyssen
mesh_terms: D003035:Cobalt / Q000008:administration & dosage* / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis*; D006801:Humans; D010328:Patch Tests / Q000706:statistics & numerical data*; D023422:Skin Irritancy Tests / Q000706:statistics & numerical data*; D012882:Skin Tests / Q000379:methods
chemical_list: D003035:Cobalt; C018021:cobaltous chloride
keywords: cobalt; contact dermatitis; dose-response; elicitation; elicitation dose; patch test; spot test