Erythema nodosum leprosum presenting as fever of unknown origin

Erythema nodosum leprosum (ENL) is an immune-mediated sequela of multibacillary leprosy that usually occurs after the initiation of treatment. We report a rare case of ENL in a 40-year-old man , with a two-year history of bilateral lower limb numbness, who presented with intermittent fever, bilateral painful shins, painful nodular rash on extremities, inguinal lymphadenopathy and oligo-arthritis over 3 weeks. Investigations revealed neutrophilic leukocytosis with high inflammatory markers. Slit skin smear revealed presence of Mycobacterium leprae with a 4+ bacillary index confirming the diagnosis. Early treatment with multidrug therapy and steroids resulted in a rapid improvement in our patient.