Allergic contact reactions to hair dyes arise mostly due to sensitization to para-phenylenediamine (PPD). Para-phenylenediamine, a derivative of p-nitroanaline, is widely used as an oxydizable hair dye and is also found in black henna tattoo. Subsequent exposure to PPD may lead to delayed type IV hypersensitivity reaction manifesting as acute contact dermatitis. Here, a 15-year-old girl is presented, who developed a hypersensitivity reaction after first exposure to hair dye. She was found to have been sensitized to PPD before, through application of black henna tatto.