A Case Series of Secondary Hemophagocytic Lymphohistiocytosis (HLH) Secondary to Dengue Infection Receiving Dexamethasone in a Tertiary Centre.

Introduction: Secondary Hemophagocytic Lymphohistiocytosis (HLH) is a condition seen in severe dengue that can be potentially fatal. Timely management using HLH-directed treatment such as steroids or etoposide have been seen to improve the outcome of patients however there is no protocol on how to manage the disease. Two criteria commonly used to guide the direction of treatment are namely the HLH-2004 criteria and the Hscore; with the latter being used more often. The best cut-off H score is 169 corresponding to a sensitivity of 93%, specificity of 86% and accurate classification of 90% of the patients. We described of five patients diagnosed with severe dengue complicated with HLH. Methods: 5 cases that were diagnosed with severe dengue with secondary HLH and received dexamethasone were reviewed retrospectively and clinical data extracted. Results: All patients had fever beyond critical or leaking phase. Four out of five cases had Hscore higher than 169 and had a mean score of 181 with only one bone marrow performed. Three patients had concurrent leaking and bleeding and three patients had fast progression of severe transaminitis during the critical phase. The mean peak ferritin level was 21077 micro/L. The only bone marrow aspiration done revealed increased macrophages and hemophagocytic activity. All patients received a short course of dexamethasone and discharged well. Conclusion: Short course dexamethasone is effective in treatment of HLH in dengue despite the concerns of administration of steroids in bleeding dengue patient. Secondary HLH in dengue remains a clinical diagnosis with no conclusive diagnostic criteria. It should be suspected in a severe dengue patient with hyperferritinemia and persistent fever. Technical difficulty of performing bone marrow during severe dengue makes conclusive diagnosis remains elusive. [ABSTRACT FROM AUTHOR]