I too had a severe allergic reaction to PPD. I've had several minor reactions over the last 10 years but this last one was severe and required Prednisone. I've used Henna (Light Mountain brand) and the problem I've encountered is that the color is inconsistent. I have black and grey (70% or so) curly hair and the henna made it look blueish, greenish sometimes. It is impossible to control the color results. Also, be warned that some products are not all henna and some do contain PPD as well.
EcoColors does contain PPD, I had a reaction to the patch test.
Has anyone heard of Sanotint Light? I saw it on a website and it is imported from Italy
http://www.lavitanuovainc.com/faq.htm. I was reading an article that mentioned that PPD is banned from France, Germany, and Sweden. The people in these countries must have an alternative dye without PPD, right?! Any European info out there?