Patch testing with a textile dye mix--a multicentre study.

Background: Disperse dyes are well-known contact sensitizers. However, they are not included in the majority of commercially available baseline patch test series.

Objectives: To investigate the outcome of patch testing with a textile dye mix (TDM) consisting of eight disperse dyes at dermatology clinics in various countries.

Patients/materials/methods: Two thousand nine hundred and seven consecutive dermatitis patients at 12 dermatology clinics representing nine countries were tested with a TDM at 6.6%, consisting of Disperse Blue 35, Disperse Yellow 3, Disperse Orange 1 and 3, and Disperse Red 1 and 17, all at 1.0%, and Disperse Blue 106 and Disperse Blue 124, each at 0.3%, provisionally included in the baseline series. Eighty-seven per cent of the patients allergic to the TDM were also tested with the eight separate dyes.

Results: Contact allergy to TDM was found in 108 patients (3.7%). The frequency of contact allergy varied from 2.1% to 6.9% in different centres. Simultaneous reactivity to p-phenylenediamine was found in 57 of the TDM-positive patients (53%). The most frequent dye allergen among the TDM-positive patients was Disperse Orange 3. The contact allergy could have explained or contributed to the dermatitis in approximately one-third of the patients for whom clinical relevance of the TDM contact allergy was recorded.

Conclusions: The TDM should be considered for inclusion in the European baseline series.