title: Is there a risk of active sensitization to PPD by patch testing the general population?
abstract: Para-phenylenediamine (PPD), a constituent of permanent hair dyes, may cause contact allergy in exposed individuals. It has previously been questioned whether a patch testing with PPD in population-based epidemiological studies is entirely safe. The Glostrup allergy studies patch tested the same cohort twice. In 1990, 567 persons were patch-tested and only one person had a (+) positive reaction to PPD. In 1998, 540 persons were re-invited to a new patch test and 365 (participation rate 68%) were re-tested. There were no positive reactions to PPD. These studies indicate that patch testing with PPD in individuals with no previous positive reactions to PPD or with only one previous positive reaction does not cause active sensitization and can be performed with minimal risk.
authors.affiliation: Department of Dermato-venerology, National Allergy Research Centre, Gentofte University Hospital, Gentofte, Denmark. jacpth01@gentoftehosp.kbhamt.dk
authors.forename: Jacob Pontoppidan
authors.initials: JP
authors.lastname: Thyssen
authors.forename: Torkil
authors.initials: T
authors.lastname: Menné
authors.forename: Niels Henrik
authors.initials: NH
authors.lastname: Nielsen
authors.forename: Allan
authors.initials: A
authors.lastname: Linneberg
mesh_terms: D000485:Allergens / Q000009:adverse effects*; D004396:Coloring Agents / Q000009:adverse effects; D003718:Denmark / Q000453:epidemiology; D017449:Dermatitis, Allergic Contact / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D006801:Humans; D010328:Patch Tests / Q000009:adverse effects*; D010655:Phenylenediamines / Q000009:adverse effects*; D012307:Risk Factors
chemical_list: D000485:Allergens; D004396:Coloring Agents; D010655:Phenylenediamines; C029728:4-phenylenediamine