Hemophagocytic Lymphohistiocytosis in Erythema Nodosum Leprosum: Case Report of an Unusual Conundrum.

Hemophagocytic lymphohistiocytosis (HLH) and erythema nodosum leprosum (ENL) result from a complex agent-host interaction and form a continuum of the same spectrum. A 30-year-old multi-gravida presented at 36 weeks gestation with fever and erythematous raised lesions over the face and upper and lower limbs after defaulting treatment for borderline lepromatous leprosy. Skin biopsy confirmed ENL, hence multi-drug therapy (MDT) and oral steroids were restarted. However, her condition worsened and she developed icterus, periorbital puffiness, pleural effusion, ascites and splenomegaly. Laboratory investigations showed pancytopenia, conjugated hyperbilirubinemia, transaminitis, elevated lactate dehydrogenase, hypertriglyceridemia, hyperferritinemia and hypofibrinogenemia. Dapsone was stopped on the suspicion of dapsone hypersensitivity but hyperbilirubinemia progressed. Diagnosis of HLH was clinched after bone marrow aspirate showed florid hemophagocytosis and subsequently, intravenous immunoglobulin (2 g/kg) over 5 days and dexamethasone were administered. The patient improved gradually with normalization of laboratory parameters and restarted MDT. This case depicts a rare and potentially catastrophic complication of ENL and emphasizes a vigil for HLH syndrome in such cases.