Monitoring contact sensitization to p-phenylenediamine (PPD) by patch testing with PPD 0.3% in petrolatum

作者：Geier Johannes^*; Ballmer Weber Barbara K; Dickel Heinrich; Frosch Peter J; Bircher Andreas; Weisshaar Elke; Hillen Uwe

来源：Contact Dermatitis, 2013, 69(1): 26-31.

DOI：10.1111/cod.12075

• active sensitization
• CAS 106-50-3
• monitoring of contact allergy
• patch test concentration
• patch testing
• p-phenylenediamine

Background Being a contact allergen of general relevance, p-phenylenediamine (PPD) is patch tested in the baseline series. However, PPD 1% in petrolatum may actively sensitize. Patch testing with PPD at 0.35% pet. proved to be safe, as far as active sensitization is concerned. Objectives To determine whether PPD 0.3% pet. reliably detects PPD sensitization. Methods Patch testing with PPD 0.3% pet. and 1% pet. synchronously was performed in consecutive patients in a multicentre study within the Information Network of Departments of Dermatology. Results Altogether, 2042 patients were patch tested. PPD 1% pet. yielded 6.0% positive reactions (n=123), and PPD 0.3% pet. yielded 4.7% (n=95). The synchronous reproducibility of PPD reactions was similar as known from parallel patch tests with identical PPD concentrations. The diagnostic properties of PPD 0.3% pet. expressed as reaction index and positivity ratio were good. Of the 123 patients reacting to PPD 1% pet., 32 (26%) had no positive reaction to PPD 0.3% pet. In 22 of these 32 patients (69%), no clinical relevance could be found. Conclusions As patch testing with PPD 0.3% pet. is reliable according to our results, we recommend replacing PPD 1% pet. in the baseline series with PPD 0.3% pet.

• 出版日期2013-7