Textile dyes Disperse Orange 1 and Yellow 3 contain more than one allergen as shown by patch testing with thin-layer chromatograms.

It is known that some patch-test preparations containing disperse dyes contain impurities with unknown relevance for the development or elicitation of contact allergy. To evaluate the significance of the impurities found in the commercial dyes Disperse Orange 1 (DO1) and Disperse Yellow 3 (DY3) regarding contact allergy in patients with known sensitivity to them. Ten patients allergic to DY3 and/or DO1 were tested with a dilution series of commercial and purified DY3 and DO1 (with water-soluble parts prepared from the commercial dyes) and with naphthalene sulfonate. Nine patients were additionally tested with thin-layer chromatograms (TLCs) made from the commercial DO1 and DY3 and with paper chromatograms made from the water-soluble part of these dyes. Eight of nine and three of six patients tested positively to the TLCs of DO1 and DY3, respectively. Among them, 4 of 8 and 2 of 3 patients, respectively, were positive also to another spot on the TLCs. One patient was positive to the paper chromatogram from the water-soluble part of DO1. None of the tested patients reacted to naphthalene sulfonate. The results of our study suggest that there are more relevant allergens in the fat-soluble and water-soluble fractions of the commercial disperse dyes.