title: Patch tests with thiurams at 0.25% pet. and 1% pet. are of equal diagnostic value.
abstract: Thiuram mix is tested in the standard series at a test concentration of 1% pet. The single thiurams (DPTD, TMTD, TMTM, TETD), however, are usually tested at 0.25% pet. in Germany. In other countries, the individual components of thiuram mix are tested at 1% pet. The German Contact Dermatitis Research Group (DKG) compared both patch test concentrations in 530 patients in order to find out if (i) a significant number of positive patch tests are missed by testing at the lower concentration, (ii) problems with irritant test reactions occur by increasing the test concentration to 1%, and (iii) the sensitivity of the thiuram mix rises when the breakdown test is done with the higher concentration. Slightly more positive reactions were seen with the higher concentration, but this increase did not reach statistical significance. The reaction index, as a measure for the relation of positive to irritant and/or questionable reactions, remained unchanged for the individual thiurams. The sensitivity of the mix also did not change when the breakdown test was performed with 1% pet. instead of 0.25% pet. Thus, we conclude that both concentrations are of equal diagnostic value in patch testing.
authors.affiliation: Information Network of Department of Dermatology, University of Göttingen, Germany. jgeier@med.uni-goettingen.de
authors.forename: Johannes
authors.initials: J
authors.lastname: Geier
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Frosch
authors.forename: Axel
authors.initials: A
authors.lastname: Schnuch
authors.forename: Monika
authors.initials: M
authors.lastname: Agathos
authors.forename: Andrea
authors.initials: A
authors.lastname: Bauer
authors.forename: Jochen
authors.initials: J
authors.lastname: Brasch
authors.forename: Gisela
authors.initials: G
authors.lastname: Gaber
authors.forename: Petra
authors.initials: P
authors.lastname: Gottlöber
authors.forename: Jürgen
authors.initials: J
authors.lastname: Grabbe
authors.forename: Martin
authors.initials: M
authors.lastname: Hartmann
authors.forename: U T A
authors.initials: UT
authors.lastname: Jappe
authors.forename: Martin
authors.initials: M
authors.lastname: Kaatz
authors.forename: Dieter
authors.initials: D
authors.lastname: Lübbe
authors.forename: Claudia
authors.initials: C
authors.lastname: Pirker
authors.forename: Olaf
authors.initials: O
authors.lastname: Gefeller
mesh_terms: D017449:Dermatitis, Allergic Contact / Q000175:diagnosis*; D006801:Humans; D010328:Patch Tests; D010577:Petrolatum; D012680:Sensitivity and Specificity; D013893:Thiram / Q000009:adverse effects
chemical_list: D013893:Thiram; D010577:Petrolatum