Patch test frequency to p-phenylenediamine: follow up over the last 6 years.
While the frequency of patch test reactivity to many cosmetic allergens has decreased over the last 20 years, we have previously shown that in our clinic, the patch test reactivity to p-phenylenediamine (PPD) has remained stubbornly high between 2.5% and 4.2% in the years when patch testing was performed with 1% PPD. Further retrospective analysis of the PPD patch test frequency over the last 6 years shows an increasing rate of PPD patch test frequency, showing an upward linear trend. This increasing trend cannot be fully explained by any increase in patch testing of Southern Asian patients or of sensitization caused by PPD exposure from 'temporary henna tattoos'. An alternative explanation may be the increasing use of permanent hair dyes.
Patel
Sheena
S
St John's Institute of Dermatology, St Thomas' Hospital, London SE1 7EH, UK.
Basketter
David A
DA
Jefferies
Donna
D
White
Ian R
IR
Rycroft
Richard J G
RJ
McFadden
John P
JP
Ho
Stephanie Y
SY
D003877:Dermatitis, Contact / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006202:Hair Dyes / Q000009:adverse effects*; D006801:Humans; D008297:Male; D010328:Patch Tests; D010655:Phenylenediamines / Q000009:adverse effects*
D006202:Hair Dyes; D010655:Phenylenediamines; C029728:4-phenylenediamine