Contact dermatitis after the application of temporary, paint-on, henna tattoos represents a well-known, potentially serious problem of active sensitization. We describe 3 cases involving 3 children of the same age who developed a severe contact dermatitis with massive face and neck swelling after application of black henna to their hair during "Purim" celebrations. All 3 cases had a history of having applied henna tattoos in the previous year with mild local reactions. Their reactions are presumed to be due to sensitization to para-phenylenediamine. Although reactions to henna are being increasingly reported, reactions of this severity seem to be rare and could lead to permanent skin changes.