A Case Report of Discoid Lupus Erythematosus Mimicking Skin Infection

<b>Background and Clinical Significance</b>: Cutaneous lupus erythematosus (CLE) is an autoimmune condition characterized by a wide range of cutaneous manifestations, classified into three major subtypes-chronic (CCLE), subacute (SCLE), and acute (ACLE)-based on clinical morphology and lesion duration. Discoid lupus erythematosus (DLE), the most common form of CCLE, predominantly affects sun-exposed areas and presents as erythematous macules that progress to well-demarcated, disc-shaped plaques. If left untreated, DLE may lead to scarring and permanent alopecia. Diagnosis is primarily clinical, with skin biopsy performed when indicated. Management includes photoprotection and topical corticosteroids, with systemic immunosuppressive therapy reserved for severe cases. <b>Case Presentation</b>: We report a case of a 38-year-old female patient presenting with confluent lesions with indurated borders and multiple pustules, initially raising suspicion of cutaneous infection. A broad differential diagnosis was considered, including fungal and bacterial infections, demodicosis, and cutaneous tuberculosis, all of which were excluded through comprehensive clinical and laboratory investigations. Ultimately, DLE was diagnosed based on serologic and histopathologic findings. During the course of immunosuppressive therapy, her condition deteriorated, and she developed pulmonary tuberculosis. <b>Conclusions</b>: The presented case underlines the rarity and broad differential diagnosis of DLE as well as the possibility of complications.