Contact sensitivity to hair dyes can be detected by the consumer open test

Maya Krasteva, Antonio Cristaudo, Barbara Hall, David Orton, Edward Rudzki, Baltassare Santucci, Hervé Toutain, John Wilkinson

Research output: Contribution to journalArticlepeer-review


To avoid allergic reactions to hair dyes, an open test ("skin sensitivity test" or "dab test") is recommended 48 hours before the hair colouring procedure. We have investigated in a multicenter study, under standardized conditions and medical supervision, the validity of this test as a practical method to detect allergy to paraphenylenediamine (PPD)-containing hair dyes in 30 PPD patch test-positive and 30 PPD patch test-negative subjects. A defined volume of a marketed hair colouring product containing 1.8% PPD was applied in an open patch test to the retroauricular area. The grading method comprised the dermatologist's clinical evaluation and objective numerical scores. Allergic reactions were elicited in all PPD-positive subjects with a maximal intensity on Day 2; no allergic reactions were elicited in PPD-negative subjects. Increased severity of reactions by the dermatologist's clinical evaluation was correlated strongly with increasing numerical scores. The "skin sensitivity test" can be considered as an effective method to detect type IV hair dye allergy and as such, as an important factor in its secondary prevention.

Original languageEnglish
Pages (from-to)322-326
Number of pages5
JournalEuropean Journal of Dermatology
Issue number4
Publication statusPublished - 2002


  • Consumer allergy
  • Hair dyes
  • Objective numerical scores
  • Open testing
  • Paraphenylenediamine
  • Skin sensitivity test

ASJC Scopus subject areas

  • Dermatology


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