A visible response to an invisible tattoo.

Invisible (or blacklight) tattoos are fast becoming the trend in the world of tattoo art, and with their rise comes the onset of associated complications. Though there have been many reports of cutaneous reactions to traditional tattoo pigments, literature regarding reactions to invisible tattoos is scarce. We report the case of a 28-year-old man who presented with an inflammatory eruption of 2 months' duration confined to the area of a recently placed invisible tattoo; the eruption was diagnosed as granulomatous dermatitis to a foreign material. Under fluorescent light, a refractile foreign material was identified in the biopsy specimen, which we believe to be melamine, one of the invisible tattoo's five ingredients. Previous cases of cutaneous reactions to invisible tattoos were attributed to polymethylmethacrylate, not a component of the tattoo in this case. To our knowledge, this is the first case implicating melamine as the cause of a granulomatous tattoo reaction. Given the rising popularity of invisible tattoos, we present this case to raise awareness of the risks associated with this alternative tattoo trend.