Case Report: Hemophagocytic lymphohistiocytosis associated with acute polymyositis

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition marked by uncontrolled histiocyte proliferation and activation, and phagocytosis of normal hematopoietic cells. This disease is rare, and a concurrent presentation with acute polymyositis is rare. A 14-year-old male was admitted to Chattogram Medical College Hospital with a high-grade fever for 25 days, generalized severe body aches, and multiple large joint pain in the lower limb for the same duration. On examination, the patient was found to have splenomegaly, tenderness in both knee joints, symmetrical proximal weakness of both lower limbs, several sensory losses, and loss of bowel and bladder control. The laboratory data showed that he had anemia, thrombocytopenia, hyperferritinemia, hypertriglyceridemia, hypofibrinogenemia, hypoalbuminemia, raised D-dimer, and serum creatine phosphokinase (S. CPK). Along with these, a bone marrow biopsy revealed hemophagocytic cells, and he was diagnosed with HLH with acute polymyositis (PM). The patient was treated with intravenous (IV) hydrocortisone and dexamethasone. Clinical stability was achieved with gradual improvement of initial symptoms and biochemical markers. The patient was discharged with oral steroids at a tapering dose and was advised to regularly follow-up.