title: The role of the antioxidant ascorbic acid in the elicitation of contact allergic reactions to p-phenylenediamine.
abstract: BACKGROUND
  An allergic contact reaction is accompanied by high oxidative stress in the skin. Pretreatment of the skin with antioxidative substances could reduce the elicitation reaction.
  
  
  OBJECTIVE
  To investigate, in a proof-of-principle study, whether pretreatment of the skin with the antioxidant ascorbic acid reduces the elicitation reaction to a p-phenylenediamine (PPD)-containing hair dye in sensitized subjects.
  
  
  METHODS
  Twelve subjects with contact allergy to PPD, a documented skin reaction to a hair dye simulation exposure model and a history of hair dye-related skin complaints were included in this study. Skin areas on the forearms were, in a left versus right design, exposed to an emulsion with ascorbic acid and an emulsion without ascorbic acid, and then to a 2% PPD-containing hair dye testing formulation. In addition, control areas were exposed to the emulsions and to the PPD-containing hair dye formulation without pretreatment. Skin reactions were graded on day (D)2 and D3.
  
  
  RESULTS
  Pretreatment with ascorbic acid emulsion resulted in a reduction in the elicitation reaction in 7 of 12 subjects at D3 (p = 0.046). No statistically significant difference was observed at D2.
  
  
  CONCLUSIONS
  Pretreatment of the skin with the antioxidant ascorbic acid had an attenuating effect on the elicitation reaction to PPD in sensitized individuals.
authors.affiliation: Department of Dermatology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands.
authors.forename: Pieter-Jan
authors.initials: PJ
authors.lastname: Coenraads
authors.affiliation: Department of Dermatology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands.
authors.forename: Tatiana A
authors.initials: TA
authors.lastname: Vogel
authors.affiliation: Department of Environmental Toxicology, Trier University, 54296, Trier, Germany.
authors.forename: Brunhilde
authors.initials: B
authors.lastname: Blömeke
authors.affiliation: The Procter & Gamble Company, Central Product Safety, 65823 Schwalbach am Taunus, Germany.|The Procter & Gamble Company, Central Product Safety, 1853, Strombeek-Bever, Belgium.
authors.forename: Carsten
authors.initials: C
authors.lastname: Goebel
authors.affiliation: The Procter & Gamble Company, Central Product Safety, 65823 Schwalbach am Taunus, Germany.|The Procter & Gamble Company, Central Product Safety, 1853, Strombeek-Bever, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Roggeband
authors.affiliation: Department of Dermatology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands.
authors.forename: Marie-Louise A
authors.initials: ML
authors.lastname: Schuttelaar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D004396:Coloring Agents / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D010328:Patch Tests / Q000379:methods*; D010655:Phenylenediamines / Q000009:adverse effects*; D011292:Premedication / Q000379:methods*; D012867:Skin / Q000187:drug effects*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D004396:Coloring Agents; D010655:Phenylenediamines; D001205:Ascorbic Acid; C029728:4-phenylenediamine
keywords: CAS no. 106-50-3; antioxidant; ascorbic acid; contact allergy; hair dye; p-phenylenediamine