Lichen planus pemphigoides after body tattooing

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Case report: Successful treatment of non-bullous lichen planus pemphigoides with dupilumab

Lichen planus pemphigoides (LPP) is a rare autoimmune bullous disease, characterized by the coexistence of lichen planus and subepidermal bullae. However, the minority of LPP patients present with papules rather than vesicles or blisters, which is defined as non-bullous LPP. The diagnosis of LPP relies on manifestations, histopathology, serological assay, and direct immunofluorescence of linear disposition of IgG and/or C3 at the basement membrane zone. Up to now, no standard therapeutic strategies have been proposed for the treatment of LPP. Herein, we describe an uncommon non-bullous LPP patient with widespread papules and erythema, probably induced by vaccination. During hospitalization, he had a poor response to the conventional treatment of topical and systemic corticosteroids, and his condition was finally alleviated by the addition of dupilumab. For LPP patients with a traditional medication failure, or who were not suitable for a higher dose of corticosteroids, a combination with dupilumab could be an alternative option.

Histopathology of Dermatologic Complications of Tattoos

ABSTRACT

Tattoos are characterized by the introduction of exogenous pigments into the dermis. Tattoos usually serve cosmetic purposes, although they may have other causes, such as traumatic pigment implants in accidents or medical-related tattoos in the context of radiotherapy. Dermatologic adverse reactions are relatively uncommon, and they include infections, immune-mediated reactions, cutaneous lesions secondary to the Koebner phenomenon, exacerbation of preexisting dermatosis, benign and malignant neoplasms, and a miscellaneous group of dermatologic conditions that may appear in a preexisting tattoo. The aim of this study is to review the types of histopathologic reactions that may appear in a preexisting permanent tattoo.