para-Phenylenediamine: the profile of an important allergen. Results of the IVDK.
BACKGROUND
para-Phenylenediamine (PPD) is an important contact allergen and primarily used in hair dyeing.


OBJECTIVE
To quantify cases of contact allergy (CA) to PPD attributed to sources of exposure.


METHODS
Patients with PPD CA, diagnosed by the Information Network of Departments of Dermatology (IVDK; n = 3307 of 83 030 patients tested), were divided into five subgroups of exposure. Demographic variables and pattern of concomitant reactions were used to characterize the subgroups further. The impact of individual factors on the risk of PPD CA was examined with a logistic regression analysis. Clinical epidemiology and drug utilization research (CE-DUR) methods were employed to estimate the 10-year prevalence of PPD CA in the general population.


RESULTS
The 4% prevalence of PPD CA in patients was extrapolated to a prevalence of 0.96% in the general population. The defined profiles were found to 'explain' the following percentages of PPD CA: (i) hair dyeing in clients 22% (0.2% of the general population); (ii) different occupational exposures, namely hair dyeing by hairdressers, paint- and rubber-associated exposures 23% (0.22% of the general population); (iii) clothing/shoes 12% (0.12% of the general population). A probable causal exposure to PPD could not be identified in about 44% of patients with PPD CA.


CONCLUSIONS
In more than 50% of cases of PPD CA, a (very) probable causal exposure was identified. In the large remainder (44%) this was not possible. 'Historical' CA without current relevance and active sensitization through patch testing (a further important exposure to PPD) must be considered in these patients.
Department of Dermatology, University of Witten/Herdecke and Klinikum Dortmund gGmbh, Dortmund, Germany. aschnuch@med.uni-goettingen.de
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A
Schnuch
H
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Lessmann
P J
PJ
Frosch
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W
Uter
D000328:Adult; D000485:Allergens / Q000009:adverse effects; D001505:Beauty Culture / Q000706:statistics & numerical data; D017449:Dermatitis, Allergic Contact / Q000453:epidemiology / Q000209:etiology*; D009783:Dermatitis, Occupational / Q000453:epidemiology / Q000209:etiology; D005260:Female; D005858:Germany / Q000453:epidemiology; D006202:Hair Dyes / Q000009:adverse effects*; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects; D010328:Patch Tests; D010655:Phenylenediamines / Q000009:adverse effects*; D015995:Prevalence
D000485:Allergens; D006202:Hair Dyes; D010655:Phenylenediamines; C029728:4-phenylenediamine