Do you dye your hair? I do. In the beginning, it was just out of curiosity, for fun. But then, when the roots started showing, I was kinda trapped into doing it on a regular basis. It has become a cycle I don't know how I'm going to get out of!

So it stresses me to read that more and more people are developing allergies to hair dyes. Apparently, the culprit is a compound called para-phenylenediamine (PPD).

Dermatologists report anecdotally that the frequency of positive reactions to PPD on patch testing is increasing. This was confirmed in a recent survey in London, which found a doubling in frequency over six years to 7.1% in a clinic for adults with contact dermatitis. This trend has also been observed in other countries.

What I want to know is whether one develops an allergy to hair dye. I mean, could it be that you're not allergic now, but can develop allergies upon repeated use and exposure?