Temporary henna tattoos have recently become increasingly popular, especially among teenagers. Combining henna with other colouring agents such as para-phenylenediamine (PPD) may increase its potential for contact sensitization, cross-reaction to related compounds, as well as life-long allergy. Several cases of contact dermatitis from temporary tattoos with black henna have been reported in the literature. We present our experiences with 4 pediatric cases of allergic contact dermatitis induced by henna tattooing and give a brief review of the literature. The agent responsible for contact allergy was proven to be PPD in 3 patients, and in one patch testing revealed positive reactions to PPD and benzocaine, as well as to wool alcohols, nickel sulphate and potassium dichromate, to previously used hair dye-all being of clinical relevance.