According to dermatologists, a surprisingly high number of hair dyes have various types of potential allergens, many of which can cause rashes on your scalp, neck and chest.
During a recent presentation at the 24th Annual Meeting of the American Contact Dermatitis Society , research from 100 hair dyes was presented. The results? 89% of the products were found to have phenylenediamine (PPD), which can cause a condition called allergic contact dermatitis.
“There’s no real reason your body should identify PPD as a pathogen, but sometimes, it does. So it activates an immune response that results in a rash,” says Dathan Hamann, a researcher at the University of Arizona who presented the study.