Tattoo allergic reaction

History

         A young lady presented two weeks after a professional-made tattoo on the dorsal surface of the hand with red tattoo reaction. The reaction was in form of pruritic scaly dermatitis confined to the red portion of the tattoo. Cinnabar (mercuric sulfide) or mercury is the pigment used to give the red color of tattoo and the red tattoo is the most common cause of delayed allergic reaction in tattoos.