Case reports of dye allergy from several countries like Britain, Belgium, Portugal, Germany and Singapore are indicating an increase in hair dye allergy incidence.

Researchers believe that the rates have grown as more and more people are coloring their hairs.

It is Para-phenylenediamine, or PPD, and its chemical cousins called aromatic amines that trigger the allergic reactions. These chemicals are present in over two-thirds of hair dyes. The reactions include eczema showing up on the face and around the hairline, face swelling up and painful bruising that often requires hospital treatments.

Existing data from Japan shows that around 13% of female high school students and 6% of women in their 20s dyed their hairs in 1992. Only 2 % of men in their 20s used the dyes. These proportions rose to 41%, 85% and 33% respectively by 2001.

Researchers conclude that people cannot stand against the cultural and commercial pressure to dying hair and such behaviors are putting them at risk of severe allergic reactions. Some youngsters continue to dye their hairs even after experiencing allergic reactions.

PPD is an acceptable ingredient in Canada and safe when used correctly, such as in products that do not come in contact with skin for a long period of time. Health Canada strongly advises a "patch test" for hair dye.
European Union allows PPD to be present up to 6% of the ingredients in hair dyes for consumers.

For the time being, there are no other available alternatives for permanent hair dyes.