Pilot-study of a simple allergy self-test in persons who have had a skin-reaction to PPD containing hair dye.

More and more people are dying their hair, and a substantial number of young
people are exposed to temporary tattoos. A principal component of hair dyes,
and of some tattoo paints is p-Phenylenediamine (PPD). PPD is an allergen, and
can occasionally cause very severe skin reactions, more severe that is usually
seen from other contact allergens.
People who suspect that they may react to hair-dye want to know whether they
are possibly allergic to it, before they dye their har or visit a hairdresser
for haidying. A full dermatological examination with patch-testing is
time-consuming, and puts constraints on the availability of dermatological
services. A simple self-test with a patch on their forearm may give an
indication about such a contact-allergy

A pilot-study to the feasibility of a simple self-patchtest with a PPD
containing hair-dye solution. The aim is to investigate whether a 30-minutes
application of a patch-test gives a positive reaction in individuals who have a
proven contact allergy to PPD.

Two patch-test chambers of 1x1 cm each will be applied to the volar forearm of
28 PPD allergic individuals for 30 minutes.
One patch-test will contain a mixture of hydrogen peroxide with a basic
hair-dye cream; the mixture has a PPD concentration of 2%.
The control patch-test will contain the same mixture, but without PPD. The
cream base consists of non-allergenic components that are used in many
cosmetics.
After an application time of 30 minutes, the two patches will be removed, and
the skin area washed with water.
Two days later (48 hours) the test-area will be read, and again three days
later (72 hours). The anticipated reaction will be a redness, which will be
graded according to the criteria of the ICDRG. The redness will disappear in a
few days, similar to the reactions that may occur after a routine patch-test in
a dermatology clinic.
Assuming a positivity rate of at least 80%, with a standard deviation of 7.5%
(95% CI +/- 15%), the number of participants will be 28.

On the day of the patch-test application the time burden will be 35 to 40
minutes at the most, in addition to travel time to the clinic. The actual
application of the patch will cause no harm or discomfort.
The time burden for reading the patch test reaction will be less than 5 minutes
on day 2 and day three. There will be a travel time burden, but the
participants will be offered to have these two readings done at their home or
at a nearby location (e.g. a health center).
It is anticipated that the majority (80%) will develop a redness, possibly with
some itching, at the site of the patch-test with the PPD containing solution.
This redness is transient, and will disappear within a few days without leaving
scars. Participants have the option to receive a one-time application of a
corticosteroid-containing cream to enhance the remission of the reaction.
Systemic effects from resorption of PPD are irrelevant at such a short exposure
time and small application area. The maximum permitted concentration of skin
contact with PPD in hair-dye is 6%, which is much higher than the test
concentration.