Severe Dengue and Associated Hemophagocytic Lymphohistiocytosis in PICU

Objectives To study the clinico-laboratory profile and outcome of children with severe dengue and dengue-associated hemophagocytic lymphohistiocytosis (HLH). Methods In this retrospective study, 22 children with laboratory confirmed severe dengue admitted to pediatric intensive care unit (PICU) were enrolled. Clinical features, laboratory parameters, and outcome were noted and compared between cases fulfilling HLH-2004 criteria and those without HLH. Results Median (IQR) age was 8 (5-10.3) y. Fever was present for mean (SD) duration of 5.3 (2.1) d. Vomiting, respiratory distress, pain abdomen and hepatomegaly were other clinical features. Thrombocytopenia, anemia and elevated serum transaminases were noted in 91%, 41% and 30% respectively; coagulopathy and hypoalbuminemia were seen in 36% each. Half (n = 11, 50%) had dengue shock syndrome. Acute respiratory distress syndrome (ARDS) (n = 7, 32%) and acute kidney injury (AKI) (n = 6, 28%) were other major organ dysfunctions. Mean (SD) duration of PICU stay was 3.6 (1.5) d with 13.6% mortality. HLH was noted in 7 (32%) cases at a median (IQR) hospital stay of 5 (2-8) d. Children with HLH had significantly higher Pediatric Index of Mortality 2 (PIM 2) score at admission and higher frequency of pain abdomen, anemia, hypoalbuminemia, elevated alanine aminotransferase (ALT) and ARDS. Length of PICU stay (5.1 vs. 2.9 d) and mortality (28.6% vs. 6.7%) were higher in HLH group, however the difference was not statistically significant. Steroids were used in 4 cases with HLH and all survived, whereas among 3 who did not receive steroids, 2 died (p = 0.23). Conclusions Severe dengue presents with life-threatening organ dysfunctions. HLH is increasingly recognized in dengue infection and maybe considered as a differential diagnosis in children with lower hemoglobin, hypoalbuminemia, elevated ALT and severe organ dysfunction.