Tattoos and tattooing. Part II: Gross pathology, histopathology, medical complications, and applications

Tattooing involves piercing the skin with needles bearing various pigments, to cause the permanent imprint of a design. The body responds to these incursions in specific and predictable ways, with initial sloughing of the overlying epidermis, variable dermal inflammation, and gradual assimilation of the pigment into macrophages. Eventually, much of the pigment is carried to the regional draining lymph nodes, with a residue staying within macrophages localized to dermal perivascular regions. The age of tattoos may be estimated, both grossly and microscopically. Tattooing can result in a variety of relatively uncommon complications and adverse reactions to the pigment, and certain infectious diseases may be inadvertently transmitted through tattooing when the instruments are inadequately sterilized, or when poor technique is used. This article, the second of three, describes the gross and microscopic pathology of both fresh and healed tattoos, and discusses the various complications (infectious and otherwise) that can occur. Tattooing has specific applications in both dermatology and plastic and reconstructive surgery, and these are also discussed.