Background: Dengue fever classically presents with fever, arthralgia, myalgia, leukopenia, and thrombocytopenia. A classical presentation with a positive serology test is usually enough to make the diagnosis in an endemic area. Case Presentation: A 30-year-old man presented with fever, leucopenia, thrombocytopenia, hepatitis, and delirium. Dengue Immunoglobulin M (IgM) serology was positive. Blood culture grew Salmonella typhi, his ferritin was raised, and bone marrow histology showed histiocytes and hemophagocytic activity. A 2-week course of ceftriaxone (60-75 mg/kg/day) and intravenous immunoglobulin (0.4 g/kg once a day) for 3 days resulted in complete resolution of his illness. Conclusion: We report a case of typhoid fever with hemophagocytic lymphohistiocytosis mimicking as dengue fever due to cytopenias and hepatitis, and dengue IgM serology was positive. Although rare, a high index of suspicion is required for early diagnosis and treatment.

Keywords: Dengue fever, typhoid, hemophagocytic lymphohistiocytosis, HLH, case report