Hemophagocytic Lymphohistiocytosis Complicating Methotrexate Toxicity.

Hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal disease caused by dysregulated activation of macrophages against one's blood cells. Major pathologic feature of HLH is hemophagocytosis. We present a case of HLH complicating methotrexate toxicity in a 65-year-old psoriatic patient with history of renal disease. Diagnosis of HLH was established as he fulfilled five out of eight HLH diagnostic criteria. This case report is presented to enlighten clinicians about the clinical entity of HLH and to suspect and recognize this rare and generally fatal disease at the earliest.