Study on Hypoallergenic Hair Dye

For patients with PPD sensitizations, it is important to find alternatives for dark hair dyes. P-toluenediamine (PTD) and potentially also 2-methoxyethyl p-phenylenediamine (ME-PPD) show cross-reactivity with PPD and therefore we want to prove that our new compounds PPD-6 and PPD-7 show no or significantly reduced cross-reactions with PPD and do not induce relevant allergic reactions in patients with proven PPD sensitizations. Our specific aims for this study are the following: A1) To show that PPD 6 and PPD 7 have reduced or optimally no reaction in standard patch tests in patients with proven allergy to PPD A2) To compare the sensitization pattern to other possible commercially available alternatives for hair dye, such as ME-PPD and PTD A3) To evaluate and rule out any possible non-specific irritant reaction of PPD-6 and PPD-7 in these patch tests (i.e. confirm in-vitro safety profile in-vivo)