title: Variation in the amount of petrolatum preparation applied at patch testing.
abstract: The elicitation of a positive patch test reaction in a given individual depends upon the dose of the sensitizer applied, the patch test technique and the occlusion time. The dose is determined by the concentration and volume/amount of test preparation applied. If the same amount/volume of a test preparation is applied all the time with the same test technique (same area of skin) and occlusion time, it is appropriate to use concentration as a dose parameter. Most contact sensitizers are incorporated in petrolatum (pet.). With pet. as vehicle, it is impossible to repeatedly apply an exact volume/amount. This study was performed to investigate the inter- and intra-individual variation of pet. preparation applied at patch testing by 3 technicians. Weighing demonstrated that the 3 technicians had about the same precision in their pet. application. The investigation demonstrates that there is both an inter-individual (statistically significant) and intra-individual variation in the amounts of pet. applied at patch testing for the 3 technicians. Presently, there is no recommendation on what amount of pet. preparation to apply, which merits a decision to be taken based on thorough investigations on the appropriate volumes of pet. preparation to be applied in various patch test systems.
authors.affiliation: Department of Occupational and Environmental Dermatology, Malmö University Hospital, Lund University, SE 205-02 Malmö, Sweden. magnus.bruze@med.lu.se
authors.forename: Magnus
authors.initials: M
authors.lastname: Bruze
authors.forename: Malin
authors.initials: M
authors.lastname: Frick-Engfeldt
authors.forename: Birgitta
authors.initials: B
authors.lastname: Gruvberger
authors.forename: Marléne
authors.initials: M
authors.lastname: Isaksson
mesh_terms: D003877:Dermatitis, Contact / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D009570:Nitriles / Q000009:adverse effects; D010328:Patch Tests / Q000592:standards*; D010577:Petrolatum
chemical_list: D009570:Nitriles; D010577:Petrolatum; C039411:1,2-dibromo-2,4-dicyanobutane