Current patch test results in consecutive patients with, and chemical analysis of, disperse blue (DB) 106, DB 124, and the mix of DB 106 and 124.
Disperse blue (DB) 106 and 124 are important textile dye allergens. However, the dye raw material is impure, leading to uncertainty regarding the actual patch test (PT) concentration. To examine, (i) the allergen content of previously and currently used DB 106 and 124 and a respective mix, and (ii) the frequency of positive PT reactions to the DB 106/124 mix and to the single compounds in consecutive PT patients. High performance liquid chromatography (HPLC) analysis and purification of DB 106 and 124, respectively. Descriptive analysis of PT data from the Information network of departments of dermatology obtained between January 2003 and December 2005. Retrospectively, 2 batches of the DB 106/124 mix proved to contain an amount of allergen different to the 1 declared (based on information of suppliers of raw material). However, since February 2005, DB 106 and 124, respectively, are available at a reliable concentration of 0.3% petrolatum. In 2005, the prevalence of positive PT reactions to both the mix (0.89%) and the single constituents combined (0.56%) did not qualify them for inclusion in the standard series. Quality control, providing accurate test concentrations of allergens based on technical grade purity raw materials is necessary for valid diagnosis of contact allergy and comparable epidemiological data.
Uter
Wolfgang
W
Department of Medical Informatics, Biometry and Epidemiology, University of Erlangen-Nürnberg, Erlangen, Germany. wolfgang.uter@rzmail.uni-erlangen.de
Hildebrandt
Stephan
S
Geier
Johannes
J
Schnuch
Axel
A
Lessmann
Holger
H
D000485:Allergens / Q000009:adverse effects / Q000737:chemistry*; D001391:Azo Compounds / Q000009:adverse effects / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D017449:Dermatitis, Allergic Contact / Q000209:etiology; D006801:Humans; D010328:Patch Tests
D000485:Allergens; D001391:Azo Compounds; C069319:Disperse Blue 124; C049175:disperse blue 106