Cutaneous reactions to temporary tattoos.

While allergic reactions to henna painting are extremely rare, we have witnessed an increasing number of reports of cutaneous reactions after henna tattooing, also called temporary tattooing. The reason for this lies in the contemporary composition of the paint, which contains paraphenylenediamine (PPD). We present six patients who developed allergic contact dermatitis after skin painting with "black henna", and who showed hypersensitivity to PPD. We discuss the issue of the short sensitization period of our patients and the reported ones.