When a Mimicker Is Mimicked: A Case report on Acid-Fast Atypical Lepromatous Leprosy Mimicking Tuberculosis

Leprosy is caused by Mycobacterium leprae, may mimic tuberculosis. We describe a 22year old woman with prolonged fever and cervical and inguinal lymphadenopathy. Initial lymph node aspirate from an outside centre showed acid fast bacilli on ZN staining using 20% sulfuric acid, leading to a diagnosis of tuberculosis and initiation of anti-tubercular therapy. Additionally, she developed ulcerative lesions over the feet after six weeks.At our centre,lesion pus revealed abundant AFB with differential decolorization. CBNAAT for tuberculosis was negative. Slit-skin smears, Fite Faraco stain and PCR confirmed multibacillary leprosy erythema nodosum leprosum. Multidrug therapy resulted in clinical improvement, highlighting diagnostic challenges.