RESUMEN
Hemophagocytic lymphohistiocytosis (HLH) is a rare, potentially life-threatening clinical syndrome characterized by hyperactivation of inflammatory mediators and harmful end-organ damage. Visceral leishmaniasis (VL)-induced HLH is a rare disease with significant diagnostic and management implications. Herein, we present a case of secondary HLH as a complication of visceral leishmaniasis in a two-year-old toddler. A 2-year-old male toddler was admitted for evaluation of a prolonged 4-week fever. Accompanying the fever, he developed progressive abdominal swelling, intermittent bilateral nasal bleeding, and repeated chest-focus infections of similar duration. The patient was acutely sick, with chronic signs of malnutrition (mid-upper arm circumference of 10.5 cm), fever (39 °C), tachypnea (70 breaths/min), tachycardia (132 beats/min), pallor, and hepatosplenomegaly. Initial investigation revealed leukopenia (2240/µl), anemia (7.3 g/dl), and severe thrombocytopenia (26,000/µl). With consideration of febrile neutropenia, the patient was started on cefepime with further revision to vancomycin and meropenem based on the culture result. After 10 days of persistent fever and poor clinical condition, an immunochromatographic rapid test with the rK39 antigen was conducted, and the patient was found to be positive for Leishmania spp. Intravenous liposomal amphotericin B (AmBisome) was initiated. On the 6th day of treatment, the patient's clinical and laboratory profiles severely deteriorated, and further laboratory investigation showed elevated triglyceride (524 mg/dl) and ferritin levels (1500 ng/mL). VL-induced secondary HLH was confirmed, and intravenous dexamethasone was initiated. Subsequently, his clinical and laboratory findings significantly improved, and he was discharged with PO dexamethasone. Our case highlights the intricate nature of VL-induced HLH and the need for high index of suspicion and timely management.