Suddenly had a very bad reaction to hair dyes. My scalp was itchy with hives and swollen glands which lasted for ages. Drs couldn't help either. I then read about Body art quality henna and applied it. I mixed 50% henna with 40% indigo and 10% cassia to get a cooler brown colour. It healed my head (it is known for that) and gave me lovely shiny hair. However, some red still poked through which i didn't like. I cautiously applied Sanotint light hair colour in light brown and waited...6 weeks later i haven't had a reaction and very pleased with colour. Also, it covered my approx 30% grey.
I'm still allergic to normal shampoos so now use PPD free natural products and will be undergoing skin patch testing in June 2010.