p-Phenylenediamine sensitization is more prevalent in central and southern European patch test centres than in Scandinavian: results from a multicentre study.
BACKGROUND
Positive patch test reactions to p-phenylenediamine (PPD) are common. PPD is used in oxidative hair dyes and is also present in dark henna temporary 'tattoos'. Cross-sensitization to other contact allergens may occur. Because subjects sensitized to PPD are at risk of clinically severe reactions upon hair dyeing, there is a need for 'current' prevalence data on PPD sensitization.


OBJECTIVE
To compare PPD patch test results from dermatitis patients tested between 2003 and 2007 in 10 European patch test centres and to analyse the causes and determine relevance of positive PPD patch test reactions.


METHODS
Patch testing was performed using PPD (1% free base in petrolatum from Trolab (Almirall Hermal GmbH, Reinbeck, Germany) or Chemotechnique (Malmö, Sweden), equivalent to 0.090 mg/cm(2) in the TRUE test from MEKOS Laboratories AS). Statistical analysis was performed using the chi-squared test.


RESULTS
The weighted average prevalence was 4.6% among 21 515 patients. PPD sensitization occurred more often in centres located in Central and Southern Europe than in Scandinavian centres (odds ratio = 2.40; 95% confidence interval = 2.07-2.78). The overall proportion of positive patch test reactions to PPD that were registered as being of either current or 'past' relevance was high (weighted average 53.6% and 20.3%, respectively). Consumer hair dyeing was the most prominent cause of PPD sensitization (weighted average 41.8%). Furthermore, occupational hair dye exposure (10.6%) and cross-sensitization to textile dyes (12.6%) were frequently reported.


CONCLUSIONS
PPD sensitization caused by exposure to hair dyes is frequent and remains a present problem for patients visiting contact dermatitis clinics, especially in patch test centres located in Central and Southern Europe.
Thyssen
Jacob Pontoppidan
JP
National Allergy Research Centre, Department of Dermato-Allergology, Gentofte Hospital, University of Copenhagen, DK-2900 Hellerup, Denmark. jacpth01@geh.regionh.dk
Andersen
Klaus Ejner
KE
Bruze
Magnus
M
Diepgen
Thomas
T
Giménez-Arnau
Ana M
AM
Gonçalo
Margarida
M
Goossens
An
A
Le Coz
Christophe
C
McFadden
John
J
Rustemeyer
Thomas
T
White
Ian R
IR
White
Jonathan M
JM
Johansen
Jeanne Duus
JD
D000328:Adult; D000485:Allergens / Q000009:adverse effects; D004396:Coloring Agents / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000453:epidemiology*; D009783:Dermatitis, Occupational / Q000453:epidemiology; D005060:Europe; D005260:Female; D006202:Hair Dyes / Q000009:adverse effects / Q000737:chemistry; D006801:Humans; D008297:Male; D010328:Patch Tests; D010655:Phenylenediamines / Q000009:adverse effects*; D015995:Prevalence; D012537:Scandinavian and Nordic Countries
D000485:Allergens; D004396:Coloring Agents; D006202:Hair Dyes; D010655:Phenylenediamines; C029728:4-phenylenediamine