Hemophagocytic lymphohistiocytosis wildfire kindled by a tropical spark: a case report on HLH secondary to typhoid fever

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening disorder of immune regulation that can rapidly progress to end-organ damage and death. HLH is characterised by uncontrolled activation of cytotoxic T lymphocytes, natural killer cells, and macrophages that can lead to a cytokine storm. Primary HLH is a rare genetic disorder seen predominantly in the pediatric population, resulting from inherited defects in genes regulating immune function. Secondary HLH, on the other hand, can affect individuals of any age and is triggered by various conditions such as infections, autoimmune diseases, or malignancies. The problems in achieving successful outcomes are the variable clinical presentation and the lack of specificity of the clinical and laboratory findings. Clinical manifestations of HLH include persistent fever, splenomegaly, cytopenias, hyperferritinemia, and organ dysfunction. Prompt recognition and treatment, which may involve immunosuppressive therapy, chemotherapy, or hematopoietic stem cell transplantation, are crucial for improving outcomes. Here we present a case of Hemophagocytic lymphohistiocytosis triggered by Typhoid fever.