Contact Allergy to Textile Dyes - Clinical and Chemical Studies on Disperse Dyes

Disperse dyes are common sensitizers among textile dyes. Contact allergy to disperse dyes has been documented in studies carried out in southern Europe, however, corresponding studies have not been performed in the Scandinavian countries.

The aim of this study was thus to evaluate the prevalence of allergic reactions to a mix of textile dyes consisting of 8 disperse dyes: Disperse (D) Blue 35, 106 and 124, D Yellow 3, D Orange 1 and 3, and D Red 1 and 17, in southern Sweden, to assess the clinical association between self-reported skin problems and contact allergy to the mix, p-phenylenediamine and related rubber substances, and to ascertain whether patch testing with the dye mix was equivalent to testing with the separate ingredients at the concentrations used in the mix. Furthermore, the purity of the 8 disperse dyes used for patch testing at various dermatology departments and the significance of impurities in preparations of the dyes with regard to contact allergy were studied.

The frequency of contact allergy to the dye mix was 1.5%, which is comparable to the values reported in southern Europe. The most common dye allergen was D Orange 1, while the frequency of test reactions to D Blue 106 and D Blue 124 was lower than expected. The mix was found to be as good a detector of contact allergy to the disperse dyes as testing with any combination of the 8 ingredients tested at the concentrations used in the mix. Contact allergy to p-phenylenediamine was a better indicator of self-reported skin reactions to textiles than the textile dye mix used in this study. Thin-layer chromatography visualized impurities in all 107 investigated patch test preparations. No single reference substance could be identified for D Blue 35. For the other dyes, the mean concentration in preparations labelled 1.0% varied from 0.25%, for D Blue 124, to 0.68%,
for D Orange 3. D Orange 3 could not be demonstrated in 4 of 15 preparations labelled D Orange 3. About 25% of the 21 patients diagnosed as being allergic to D Blue 106 and D Blue 124 only reacted to impurities in the patch test preparations when tested with thin-layer chromatograms and a dilution series of commercial and purified D Blue 106 and D Blue 124.