title: Finding the optimal patch test material and test concentration to detect contact allergy to geraniol.
abstract: BACKGROUND
  Geraniol is a commonly used fragrance terpene, and is tested in the baseline series in fragrance mix I. Geraniol is a pro-hapten and a pre-hapten, and sensitizers are formed in the autoxidation and skin metabolism of geraniol. Previous patch testing with air-exposed (oxidized) geraniol has suggested that oxidized geraniol could be a better marker for contact allergy to geraniol than pure geraniol.
  
  
  OBJECTIVE
  To find the optimal patch test substance and concentration for detecting contact allergy to geraniol.
  
  
  METHODS
  Six hundred and fifty-five patients were patch tested with pure and oxidized geraniol at 4.0%, 6.0% and 11.0% in petrolatum. Before patch testing, the irritant properties of pure and oxidized geraniol were studied in 27 patients at 2.5%, 5.0%, 10.0% and 20.0% pet.
  
  
  RESULTS
  Pure geraniol detected positive reactions in 0.15-1.1% of the patients, and oxidized geraniol detected positive reactions in 0.92-4.6% of the patients. Reactions to pure geraniol in patients not reacting to oxidized geraniol indicated metabolic activation of geraniol. Neither pure nor oxidized geraniol gave significant irritant reactions.
  
  
  CONCLUSIONS
  Increasing the test concentrations of pure and oxidized geraniol enables the detection of more cases of contact allergy. Oxidized geraniol detects more patients than pure geraniol, but patch testing with only oxidized geraniol does not detect all cases of contact allergy to geraniol.
authors.affiliation: Department of Dermatology, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden.
authors.forename: Lina
authors.initials: L
authors.lastname: Hagvall
authors.forename: Ann-Therese
authors.initials: AT
authors.lastname: Karlberg
authors.forename: Johanna B
authors.initials: JB
authors.lastname: Christensson
mesh_terms: D000080462:Acyclic Monoterpenes; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens; D015331:Cohort Studies; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007509:Irritants; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D010147:Pain Measurement; D010328:Patch Tests / Q000379:methods*; D012680:Sensitivity and Specificity; D013729:Terpenes / Q000009:adverse effects* / Q000276:immunology; D055815:Young Adult
chemical_list: D000080462:Acyclic Monoterpenes; D000485:Allergens; D007509:Irritants; D013729:Terpenes; C007836:geraniol