Hemophagocytic Lymphohistiocytosis Secondary to Visceral Leishmaniasis: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical entity characterized by fever, constitutional symptoms, and hepatosplenomegaly associated with the presence of hemophagocytosis in the bone marrow and other organs. Visceral leishmaniasis (VL) is a severe zoonotic disease hypoendemic in Portugal, particularly in the Alto Douro region. We report the case of a 21-year-old female patient with a recent diagnosis of human immunodeficiency virus (HIV) infection, stage C3, in the context of severe Pneumocystis jirovecii pneumonia, who presented to the emergency department with fever, erythematous rash on the upper limbs and trunk, choluria and jaundice, one week after starting antiretroviral therapy (ART). On admission to the emergency department, she was febrile and tachycardic, but hemodynamically stable. Blood tests showed pancytopenia and slight cholestasis. She was diagnosed with toxic hepatitis and hematologic toxicity secondary to ART and cotrimoxazole, and both therapies were discontinued, switching prophylaxis to atovaquone. During hospitalization, she maintained a fever despite empirical antibiotic therapy with piperacillin/tazobactam and worsening pancytopenia. Microbiological tests were negative. Blood work revealed an elevated ferritin and triglycerides. Presenting multiple criteria for hemophagocytic lymphohistiocytosis, she was submitted to a bone marrow aspirate, showing Leishmania amastigotes and aspects of hemophagocytosis. Diagnosed with HLH secondary to VL, she received treatment with liposomal amphotericin B, with clinical and analytical improvement. Given the rarity of this entity, its diagnosis and treatment can represent real challenges in clinical practice. Early diagnosis reduces morbidity and mortality.