Abstract
Background
Haemophagocytic Lymphohistiocytosis (HLH) is an uncommon systemic inflammatory clinical syndrome associated with numerous conditions and a rare complication of dengue associated with significant mortality and morbidity even with appropriate treatment. The outcome is further poor if the diagnosis is delayed or left untreated. Therefore a high degree of clinical suspicion is paramount in the diagnosis of HLH, especially in an atypical presentation of dengue infection.
Case Presentation
A 17-year-old boy with a non-significant past medical history admitted with a four-day history of fever, headache, nausea, vomiting, and loose stool. On admission, he was hemodynamically stable and managed as serologically confirmed dengue fever. On the 5th day of fever, he entered the critical phase, which was uncomplicated except for high fever spicks. Even after the critical phase was over, he had ongoing high fever spicks, hepatosplenomegaly with persistent thrombocytopenia, neutropenia and anaemia. Serum ferritin level was > 3000 ng/ml, while the triglyceride level was 314 mg/dl. Bone marrow biopsy revealed an increased haemophagocytic activity. Secondary HLH was diagnosed based on criteria used in the HLH-2004 trial and successfully managed with intravenous dexamethasone 10 mg/body surface area/day for the first two weeks followed by tapering of course over eight weeks.
Conclusion
Though this is a rare complication, the clinician must suspect HLH in expanded dengue syndrome complicated with ongoing fever, splenomegaly with cytopenias, and necessary investigations to establish a firm diagnosis. Early treatments will result in promising outcomes while preventing complications and reducing mortality.