Clinicodermoscopic and immunopathological profile of non-infectious non-eczematous inflammatory tattoo reactions: A retrospective study from a tertiary care centre of East India

Introduction: Tattoo-associated complications are on the rise due to the popularity of decorative tattoos in recent years. The exact pathogeneses of various tattoo reaction patterns are still unclear, and their dermoscopic details are sparsely reported.Aim: We aimed to retrospectively study the clinical, dermoscopic and immunopathological details of patients with non-infectious, non-eczematous inflammatory tattoo reaction patterns in a tertiary care centre of East India.Method: The clinical, dermoscopic and pathological details of all the patients who had non-infectious, non-eczematous inflammatory tattoo reactions were collected. In all the cases, immunohistochemistry was done for CD1a, CD3, CD4, CD8, FoxP3, CD20 and CD56.Results: A total of five patients of skin phototypes IV and V and six tattoo reactions were analysed. Five lesions had reactions at the site of a black tattoo, and one at the site of red tattoo. Clinically, the patients presented with erythematous or blue-grey flat-topped to verrucous papules and plaques. Dermoscopic features were dominated by a central white to pink-white structureless area, a peripheral grey-white to bluish-white structureless area, white scales, comedo-like opening with keratotic plugging, milia-like cysts and shiny white structures. Pathologically, except for one lesion that only showed a lichenoid reaction pattern in the red tattoo, all had a combination of reaction patterns. Immunohistochemistry showed increased epidermal and dermal Langerhans cells, predominantly CD8 positive T cells in the epidermis and dermis, sparse dermal B cells and CD4 positive T cells, reduced T regulatory cells and a complete absence of CD56 positive NK cells.Limitations: Small sample size was the limitation of the study.Conclusion: The clinical morphology and dermoscopy may not differentiate between various types of non-infectious non-eczematous inflammatory tattoo reactions. The immunological profile supports a delayed hypersensitivity reaction due to contact sensitisation to tattoo pigment, and CD8 positive T cells play a central role in executing various pathological reaction patterns, both in the epidermis and dermis.