A Scopic Review on the Diagnostic Dilemmas and Newer Treatment Modalities in Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis is a rare and fatal systemic illness arising secondary to an immune dysregulation .Primary HLH is due to genetic defects and secondary HLH is caused due to unchecked macrophage recruitment following an acquired trigger. It is often diagnosed late in view of its rarity and similarities of presentation to sepsis and SIRS. A compelete curative solution to this problem is hematopoietic stem cell transplant, though secondary cases are often seen to have sustained remission with immune-chemotherapy COVID 19 has also been postulated to cause a HLH like scenario with blunted NK cell number and function. Recent advances in this field comprising of various immunosuppressant based regimens, myeloablative therapies preceding stem cell transplant and improved techniques of stem cell transplant have improved the outcomes. Here we try to present the pathogenesis, etiology, diagnostic criteria and the dilemmas, various treatment strategies, prognostic markers and the most recent researches regarding this rare disease.