Actinomyces Infection Leading to Pseudoepitheliomatous Hyperplasia Within a Tattoo

A Caucasian woman in her 40s presented with a one-year history of raised, dry, pruritic papules on the tattoo on the left medial lower leg she received six months prior. Examination revealed multiple open comedones and pustules coalescing into an edematous plaque, limited to the red portions of the tattoo. Histological examination revealed pseudoepitheliomatous hyperplasia, tattoo ink, and brisk lymphohistiocytic inflammation, suggestive of an infectious process. A wound culture grew Actinomyces neuii, and she was subsequently started on amoxicillin 500 mg TID for six months. Topically, she applied mupirocin ointment daily. Subsequent clinic visits demonstrated flattening and resolution of the papules and comedones on this regimen. Tattoos have risen in popularity since the 1970s, and some estimates have found that 10-20% of people of Western cultures have at least one tattoo. Tattoo complications may occur with a broad spectrum of clinical findings. Allergies, pigment foreign body granulomatous reactions, and infections are the most common complications in tattoo. Tattoo infections are commonly due to endogenous bacteria such as Streptococci and Staphylococci species or exogenous agents, leading to viral hepatitis or HIV. This report describes a case of an Actinomyces infection involving the red pigment of a tattoo. Red pigment within tattoos is the most common cause of cutaneous reactions to tattoos. The most common reaction patterns include allergic dermatitis, photosensitivity, granulomatous, lichenoid, and pseudolymphomatous reactions. We describe a case of PEH secondary to Actinomyces neuii infection limited to the red portions of a tattoo. To our knowledge, this is the first case in which Actinomyces species has been implicated in a tattoo infection. Actinomyces species are naturally found in mucous membranes of the mouth, gastrointestinal, and genitourinary tract. Potential niduses for infection in this case could include the use of dirtied instruments, contaminated pigments, or lack of sterility during the procedure. While Actinomyces rarely cause infections in humans, cutaneous infections typically manifest as a soft tissue infection often located on the head or neck, requiring treatment with antibiotics and incision and drainage. Primary cutaneous Actinomycosis is rare; they are typically chronic, recur after short courses of antibiotic treatment and lead to the formation of granules. Actinomyces neuii infection has only been reported in approximately one hundred cases, most commonly associated with abscesses, infected atheromas and diabetic ulcers. One case of A. neuii has been reported as a superinfection of hidradenitis suppurativa. Bacterial infections of tattoos are most commonly associated with Staphylococci or Streptococci infections. Mycobacteria infections of tattoos have also been reported; M. haemophilum is thought to have a predilection for tattoos and extremities as it requires low incubation temperature and iron supplementation for growth. While reactions within red tattoos and bacterial infections of tattoos may be relatively common, infection of the red component of a tattoo with Actinomyces has not yet been described. Biopsy and evaluation for bacterial infections such as Actinomyces should be considered within the differential of a red tattoo reaction.https://scholarlycommons.henryford.com/merf2020caserpt/1059/thumbnail.jp