Contact Allergy to Hair Dyes

Many strong and extreme sensitizing chemicals, such as para-phenylenediamine (PPD), toluene-2,5-diamine (TDA) and other aromatic amines or cross-reacting substances, are ingredients in hair dye products. The chemistry of hair dyeing and the immunological reactions to the potent sensitizing hair dye components are complex and have not been fully clarified up until now. Recently 2-methoxymethyl-p-phenylenediamine (ME-PPD), a PPD derivate with moderate skin-sensitizing properties, was developed. Although developed for the prevention of sensitization, ME-PPD appears to be tolerated in some PPD/TDA-allergic individuals