title: p-Phenylenediamine allergy: the role of Bandrowski's base.
abstract: p-Phenylenediamine (PPD) is a commonly used hair-dye and a potent skin allergen. The mechanism of sensitization is unknown, as PPD is protein unreactive. We studied Bandrowski's base (BB), a PPD trimer, as well as 1,4-benzoquinone (BQ), a PPD hapten. PPD patch-test positive patients were patch-tested to BB and BQ. All tests were negative to 0.01% BQ and 0.01% BB. Five of 14 (35.7%) tested had true positive reactions to 0.1% BQ. One percent BQ was found to be irritant. Seven of 43 tested (16%) were positive to either 0.1% or 1% BB. The positive reactions to BB were weak, even when PPD reactions were strong. Mice lymph node assay gave EC3 values of 0.14% for PPD compared with 0.03% for BB. Therefore, BB is approximately 10 times more potent than PPD, taking into account the molarity. We suggest that while PPD may act as a prohapten, there is probably a spectrum of antigenic determinants in vivo. BB may be bound or metabolized by keratinocytes before it reacts with Langerhans cells.
authors.affiliation: St John's Institute of Dermatology, St Thomas' Hospital London, UK. jonathanmlwhite@hotmail.com
authors.forename: J M L
authors.initials: JM
authors.lastname: White
authors.forename: P
authors.initials: P
authors.lastname: Kullavanijaya
authors.forename: I
authors.initials: I
authors.lastname: Duangdeeden
authors.forename: R
authors.initials: R
authors.lastname: Zazzeroni
authors.forename: N J
authors.initials: NJ
authors.lastname: Gilmour
authors.forename: D A
authors.initials: DA
authors.lastname: Basketter
authors.forename: J P
authors.initials: JP
authors.lastname: McFadden
mesh_terms: D000818:Animals; D016227:Benzoquinones; D004396:Coloring Agents / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology; D009783:Dermatitis, Occupational / Q000175:diagnosis* / Q000209:etiology; D006202:Hair Dyes; D006241:Haptens; D006801:Humans; D007159:Immunologic Tests; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D010655:Phenylenediamines / Q000009:adverse effects*; D012882:Skin Tests; D013785:Thailand; D006113:United Kingdom
chemical_list: D016227:Benzoquinones; D004396:Coloring Agents; D006202:Hair Dyes; D006241:Haptens; D010655:Phenylenediamines; C051597:Bandrowski's base; C004532:quinone; C029728:4-phenylenediamine