Hemophagocytic Lymphohistiocytosis Associated With Polyserositis and Salmonella typhi Infection

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal disease characterized by excessive immune response activation. Numerous conditions, including infectious etiologies, are implicated in its development. We report the case of a 16-year-old girl with HLH associated with polyserositis and Salmonella typhi infection. A 16-year-old girl presented with a high-grade fever and abdominal pain that had been ongoing for 20 days. She had been treated for malaria at a local hospital but was referred to our hospital due to the worsening of her condition. On examination, she was found to have an enlarged liver and spleen, pale skin, and hypotension, with bilateral basal crackles on chest examination. Her blood profile revealed pancytopenia, elevated C-reactive protein, and a deranged coagulation profile. Peripheral smears showed anisocytosis, microcytes, hypochromia in RBCs, and a few platelet clumps. A bone marrow biopsy revealed increased megakaryocytes and hemophagocytes. Ultrasound and computed tomography of the abdomen and pelvis showed hepatosplenomegaly, pericholecystic edema, mild ascites, and long-segment diffuse colonic wall thickening, suggesting pancolitis. Blood culture revealed S. typhi, which is rarely associated with HLH. The patient was started on the HLH-2004 protocol and showed improvement on the fourth day of initiating therapy, but due to a delayed diagnosis, the patient collapsed on the sixth day of admission. HLH is a rare but life-threatening disease with various underlying causes. The diagnosis of HLH is challenging, and early diagnosis and prompt treatment are crucial for a better prognosis. The association between HLH and S. typhi infection is rare, and this case highlights the importance of considering unusual etiologies in HLH. Clinicians should be vigilant about this association, especially in endemic regions, to ensure early diagnosis and prompt treatment.