Infection-associated Hemophagocytic Lymphohistiocytosis: An Unusual Clinical Masquerader.

Hemophagocytic lymphohistiocytosis (HLH) secondary to an infection is a great impersonator. It is caused by hyperimmune activation, which leads to a wide array of hematological abnormalities. If the disease is untreated, it is usually fatal. We report the case of a four-year-old girl who presented to our tertiary care hospital with high-grade fever, frequent loose stools, and bleeding from the lips and gums. Investigations showed pancytopenia, hyperferritinemia, hypofibrinogenemia, and hypertriglyceridemia whereas the bone marrow biopsy revealed hemophagocytosis with trilineage suppression. Blood cultures grew Salmonella typhi. After ruling out other possibilities, the diagnosis of HLH was made as per the HLH-2004 diagnostic criteria. The patient responded well to culture-sensitive antibiotics and supportive treatment. We discuss the diagnosis and clinical course of this unique case and strive to create awareness about secondary HLH induced by common diseases, such as typhoid fever.