Erythema Nodosum Leprosum in a Patient with Borderline Lepromatous Leprosy: A Case Report

Leprosy, caused by Mycobacterium leprae, presents on a spectrum ranging from tuberculoid to lepromatous disease. Borderline lepromatous leprosy represents an unstable immunological state that predisposes patients to immune-mediated reactions, including erythema nodosum leprosum (ENL), a severe inflammatory complication.

We report a case of a 62-year-old female with borderline lepromatous leprosy who presented with recurrent facial cellulitis and later developed disseminated ENL. She was initially diagnosed following a series of facial infections and confirmatory skin biopsy. Months later, she developed systemic inflammatory lesions consistent with ENL, requiring hospitalization. She was treated with high-dose corticosteroids for ENL and methotrexate to treat type 1 reaction and continued multidrug therapy (MDT) with minocycline, rifampin, and clarithromycin for leprosy, which led to significant clinical improvement.

This case highlights the diagnostic challenges of leprosy in the United States and the importance of recognizing ENL as a severe immunologic complication requiring prompt intervention. A multidisciplinary approach is essential for optimal patient outcomes.