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Two sensitizing oxidation products of p ‐phenylenediamine patch tested in patients allergic to p ‐phenylenediamine
Author(s) -
Young Ewa,
Zimerson Erik,
Bruze Magnus,
Svedman Cecilia
Publication year - 2016
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/cod.12488
Subject(s) - p phenylenediamine , chemistry , thin layer chromatography , chromatography , serial dilution , thin layer , patch test , allergy , organic chemistry , medicine , layer (electronics) , immunology , alternative medicine , pathology
Summary Background The results from a previous study indicated the presence of several possible sensitizers formed during oxidation of the potent sensitizer p ‐phenylenediamine ( PPD ) to which PPD ‐sensitized patients might react, in various patterns. Objectives To extract and analyse a yellow spot from a thin‐layer chromatogram with oxidized PPD , to which 6 of 14 (43%) PPD ‐positive patients had reacted in a previous study, in order to identify potential sensitizer(s) and to patch test this/these substance(s) in the 14 PPD ‐positive patients. Methods The yellow spot was extracted from a thin‐layer chromatogram of oxidized PPD , and two substances, suspected to be allergens, were identified by analysis with gas chromatography mass spectrometry ( GCMS ). The 14 PPD ‐positive patients, who had been previously tested with the thin‐layer chromatogram of oxidized PPD , participated in the investigation, and were tested with dilutions of the two substances. Results GCMS analysis identified 4‐nitroaniline and 4,4′‐azodianiline in the yellow spot. Of the 14 PPD ‐positive test patients, 5 (36%) reacted to 4‐nitroaniline and 9 (64%) reacted to 4,4′‐azodianiline. Conclusion The results show that 4‐nitroaniline and 4,4′‐azodianiline, formed during oxidation of PPD , are potent sensitizers. PPD ‐sensitized patients react to a high extent to concentrations equimolar to PPD of 4‐nitroaniline and 4,4′‐azodianiline.