Perforating granulomatous dermatitis reaction to exogenous tattoo pigment: a case report and review of the literature.

: The majority of cutaneous hypersensitivity reactions to exogenous tattoo pigments can be histologically classified as lichenoid or granulomatous. The etiology is still uncertain but is generally accepted to be a delayed-type hypersensitivity reaction to either the pigment itself or its carrier solution. In this report, we review the literature concerning adverse reactions to tattoos. In addition, we describe the second case of a localized granulomatous dermatitis to the red dye within a tattoo that histologically resembled granuloma annulare. This is the first reported example of a perforating granuloma annulare-like reaction.