Delayed Plasma Leakage Associated with Dengue Infection: A Case Report

Introduction. Dengue haemorrhagic fever (DHF) is characterized by plasma leakage during the critical phase of illness, typically occurring around defervescence between illness days 4 and 7. Delayed plasma leakage beyond this period is rarely described. Case Report. We report a diagnostically challenging case of dengue in a previously healthy young woman from a dengue-endemic region, in whom plasma leakage was detected on illness day 13, raising the possibility of a delayed critical phase, though a sequential febrile illness followed by dengue infection could not be excluded. The patient initially developed high-grade fever, vomiting, arthralgia, and myalgia, which resolved after three days. After a three-day period of transient clinical improvement, severe headache, abdominal pain, and recurrent vomiting developed without recurrence of fever. She was admitted on day 12 with thrombocytopenia and marked transaminitis. On day 13 of illness, ultrasonography demonstrated free fluid in the hepatorenal pouch and right pleural cavity, consistent with plasma leakage, while dengue IgM and IgG antibodies were positive. The patient was managed as DHF with careful fluid monitoring and recovered uneventfully. Conclusion. This case highlights the importance of considering dengue in patients from endemic settings even when presentation is atypical, afebrile, or temporally delayed. Although a delayed critical phase is possible, sequential febrile illnesses with subsequent dengue infection could not be excluded because early virological confirmation was unavailable. Careful monitoring for thrombocytopenia and plasma leakage remains essential even in apparently recovering patients.