Background: Dengue-associated hemophagocytic lymphohistiocytosis (DA-HLH) is a rare but severe hyperinflammatory complication of dengue. Its clinical overlap with severe dengue often delays recognition. We describe the clinical, laboratory and therapeutic characteristics of pediatric patients with DA-HLH in a dengue-endemic region of Latin America. Methods: We conducted a retrospective cohort study of pediatric patients diagnosed with DA-HLH at a tertiary-care center in Cali, Colombia, between 2013 and 2024. HLH was diagnosed using HLH-2004 criteria and supported by the HScore. Clinical features, laboratory parameters, treatment regimens and outcomes were analyzed. Associations between extreme biomarker values (below Q1 or above Q3) and mortality were assessed using Fisher exact test. Results: Nineteen patients were included, with a median age of 7 years. Fever and cytopenias were present in all cases, and hepatomegaly was frequently observed. Hyperferritinemia occurred in nearly all patients. Viral coinfections—most commonly Epstein–Barr virus and cytomegalovirus—were identified in over one-third of cases. Overall mortality was 21.1% and occurred exclusively among patients with significant underlying comorbidities. In this exploratory analysis, elevated total bilirubin was the only laboratory parameter associated with mortality. Conclusions: DA-HLH should be considered in pediatric patients with dengue who present with persistent fever, cytopenias, hepatic dysfunction and marked hyperferritinemia. In this exploratory analysis, elevated bilirubin appeared to reflect severe systemic and hepatic involvement rather than an independent prognostic factor, while viral coinfections may contribute to disease severity. Early recognition and individualized immunomodulatory management are essential, and larger multicenter studies are needed to validate these findings.
Posada et al. (Mon,) studied this question.