title: Recommendation of appropriate amounts of petrolatum preparation to be applied at patch testing.
abstract: BACKGROUND
  No recommendation exists on the amount of petrolatum (pet.) preparation to be applied in a Finn Chamber or van der Bend Chamber.
  
  
  OBJECTIVE
  The aim of this study was to determine the appropriate amount of pet. preparation to apply in the Finn and van der Bend chambers.
  
  
  METHODS
  12 volunteers were patch tested with green-coloured pet. in Finn and van der Bend chambers on the back on 3 occasions. Doses were 10, 15, 20, 25, and 30 mg initially and on second and third occasion, 10 mg was removed in van der Bend Chambers and 35 mg was added. On day 2, the test sites were scored. A negative test equalled a test area not covered to 100%. A positive test meant a completely green-coloured test area. Minor and major spreading was noted. The amount of pet. preparation yielding at most 5% negative reactions and having the least number of reactions with major spreading equalled the appropriate amount.
  
  
  RESULTS
  For van der Bend Chambers, all doses yielded more than 5% negative reactions. For the Finn Chamber, 30, 25, and 20 mg pet. yielded less than 5% negative reactions and with major spreading in 60%, 40%, and 25% of test sites.
  
  
  CONCLUSIONS
  20 mg pet. preparation was the optimal dose for the Finn Chambers.
authors: Department of Occupational and Environmental Dermatology, Lund University, University Hospital, Malmö, Sweden. magnus.bruze@med.lu.se
authors: Magnus
authors: M
authors: Bruze
authors: Marléne
authors: M
authors: Isaksson
authors: Birgitta
authors: B
authors: Gruvberger
authors: Malin
authors: M
authors: Frick-Engfeldt
mesh_terms: D000328:Adult; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000295:instrumentation / Q000592:standards*; D010577:Petrolatum / Q000008:administration & dosage
chemical_list: D010577:Petrolatum