Successful management of scrub typhus-associated hemophagocytic lymphohistiocytosis with doxycycline and immunomodulation: a case report.

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a fatal hyperinflammatory complication of scrub typhus, often with delayed diagnosis. This case report aims to detail the clinical trajectory and successful management of scrub typhus-associated HLH in a child, highlighting key diagnostic clues.

CASE PRESENTATION: A previously healthy 14-year-old boy from a scrub typhus-endemic area presented with prolonged high fever, cough, and lethargy. Physical examination revealed a pathognomonic eschar.

RESULTS

Laboratory findings fulfilled HLH-2004 diagnostic criteria, including cytopenias, hyperferritinemia (>3,000 ng/mL), hypofibrinogenemia, and hemophagocytosis on bone marrow aspirate. The patient was diagnosed with secondary HLH triggered by scrub typhus. Immediate treatment with oral doxycycline, combined with immunomodulation using intravenous immunoglobulin and dexamethasone, led to fever resolution within 72 h and full recovery.

CONCLUSION

This case highlights that in pediatric scrub typhus, a rapid decline in platelets/fibrinogen and a sharp rise in ferritin/LDH should alert clinicians to possible HLH. Early combined therapy targeting both the infection (e.g., doxycycline) and the cytokine storm (e.g., immunomodulators) may be beneficial for favorable outcomes.