Ultimate tips for naturally colouring your hair 1. Henna for red and auburn ... Always perform a patch test to check for allergies or sensitivities before applying any natural dye to your entire ...

Methods: A retrospective analysis of patch-test results since October 2006 was done and yielded 28 patients allergic to PPD who were also tested with a hair dye series. From January 2004 through ...

patients who are allergic to both PPD and PTDS need to avoid hair dye or use henna-based products, she added. Looking ahead, more research is needed on the benefits of expanded series patch ...