Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease of immune dysregulation characterized by unchecked inflammatory responses leading to end-organ dysfunction. Primary HLH results from inherited mutations that impair the capacity for immune regulation; secondary HLH arises from the inappropriate response to an immune stimulus, such as infection, malignancy or autoimmunity. What is less well known is…
![Figure 1A–C: Arrows denote hemophagocytic histiocytes.](https://www.the-rheumatologist.org/wp-content/uploads/2020/08/THR_0820_pg35-slider-150x150.png)