DOI: https://doi.org/10.36347/sasjm.2026.v12i06.011

Pages: 637-641

Background: Cutaneous tuberculosis (CTB) is a rare extrapulmonary manifestation of Mycobacterium tuberculosis infection. Erythema induratum of Bazin (EIB) is a tuberculid a hypersensitivity reaction to mycobacterial antigens presenting as recurrent nodular lesions predominantly on the lower limbs of women. Its diagnosis is challenging, particularly when classical granulomatous histopathology is absent and pulmonary investigations are unremarkable, leading to potential misdiagnosis as nodular vasculitis or panniculitis of other etiologies. Case Presentation: We report the case of a 35-year-old immunocompetent Moroccan woman who presented with a 4-month history of recurrent violaceous nodules on both lower limbs, associated with anorexia and weight loss. Skin biopsy demonstrated a non-specific lobular panniculitis with focal necrosis, without typical epithelioid or Langhans giant cell granulomas. PCR analysis of the biopsy specimen was positive for Mycobacterium tuberculosis complex. Tuberculin skin test was positive (induration 10 mm). Sputum smear microscopy, GeneXpert MTB/RIF assay, and chest radiography were all negative. Conclusion: The patient was treated with standard antituberculous therapy (2RHZE/4RH) and achieved complete resolution of skin lesions. This case highlights that cutaneous tuberculosis can perfectly mimic nodular vasculitis, that the absence of classic granulomatous histology does not exclude the diagnosis, and that PCR on skin biopsy is a decisive diagnostic tool in tuberculosis-endemic settings.