RESUMEN
Plasmodium vivax is the most common malaria agent in the world, transmitted by vectoring of anopheles mosquitoes. In the clinical course of the disease, non-specific signs of infection (fever, myalgia, joint pain, nausea, vomiting, etc.) can be seen. Hemophagocytic lymphohistiocytosis; also known as hemophagocytic syndrome, is a rapid-onset and life-threatening clinical condition that develops as a result of uncontrolled immune activation and hypercytokinemia. In this case report, a case who developed hemophagocytic syndrome while under treatment for P.vivax infection was presented. A 37-year-old male patient applied to us with the complaints of high fever, chills-shivering and weakness, started on his return from Sudan. Upon admission, the fever was 40°C, the pulse was rhythmic and 115/minute, the respiratory rate was 24/minute, and the blood pressure was 80/49 mmHg, and he was followed up in the intensive care unit due to the signs of systemic inflammatory response syndrome. During the investigation of the etiology of fever, it was learned that he did not receive prophylaxis for malaria during his stay in Sudan. Thin and thick blood smears were examined. P.vivax infection was detected in the patient and the treatment was initiated, a bone marrow aspiration biopsy was performed with the prediagnosis of hemophagocytic syndrome with persistent fever, deepening of thrombocytopenia, findings of hyperferritinemia, hypertriglyceridemia, hepatosplenomegaly, and myeloid serial hemophagocytosis in the 48th hour of the treatment. In addition to antimalarial therapy, clinical and laboratory response was obtained with polyclonal intravenous immunoglobulin (IVIG) therapy.