For both groups: 
Patients aged from 18 to 65 years old. 
Both genders eligible for study. 
Female participants must use a contraceptive method. 
Feasibility of patch testing. 
Participants must be able to understand and sign the Informed Consent, and comply with all aspects of the protocol. 
Patients must be registered in a social security system or with a health insurance coverage 
 First group: allergic patients 
Patients with allergic contact dermatitis to para-phenylenediamine (PPD) based on a history of PPD contact dermatitis and positive PPD patch tests. 
 Second group : healthy volunteers 
No history of PPD allergic contact dermatitis, with a negative PPD patch test. 

NCT00445029_inc_T1
Person
aged
NCT00445029_inc_T2
Value
from 18 to 65 years old
NCT00445029_inc_T3
Person
Female
NCT00445029_inc_T4
Procedure
contraceptive method
NCT00445029_inc_T5
Condition
allergic contact dermatitis
NCT00445029_inc_T6
Drug
para-phenylenediamine (PPD)
NCT00445029_inc_T7
Condition
contact dermatitis
NCT00445029_inc_T8
Drug
PPD
NCT00445029_inc_T9
Measurement
PPD patch tests
NCT00445029_inc_T10
Value
positive
NCT00445029_inc_T11
Scope
PPD contact dermatitis and positive PPD patch tests
NCT00445029_inc_T12
Condition
allergic contact dermatitis
NCT00445029_inc_T13
Drug
PPD
NCT00445029_inc_T14
Negation
No
NCT00445029_inc_T15
Measurement
PPD patch test
NCT00445029_inc_T16
Value
negative
NCT00445029_inc_T17
Scope
negative PPD patch test
NCT00445029_inc_T18
Condition
allergic
NCT00445029_inc_T19
Observation
healthy
NCT00445029_inc_T20
Mood
Feasibility of
NCT00445029_inc_T22
Person
Both genders
NCT00445029_inc_T23
Mood
be able to
NCT00445029_inc_T26
Scope
understand and sign the Informed Consent, and comply with all aspects of the protocol
NCT00445029_inc_T27
Observation
registered in a social security system
NCT00445029_inc_T28
Observation
health insurance coverage