A 35-year-old man from a dengue-endemic area presents on day 3 of fever with myalgia, retro-orbital pain, platelet count 68 × 10⁹/L, leukopenia, and a positive dengue NS1 antigen. On day 5, he develops abdominal pain, persistent vomiting, and clinical signs of fluid accumulation. BP 100/70. This phase of dengue is characterized by:
- A Primary viremic phase — managed with antivirals
- B Recovery phase — excess IV fluids must be mobilized
- C Critical phase (plasma leakage phase) — requiring careful IV fluid management ✓
- D Secondary dengue infection with dengue hemorrhagic fever requiring FFP transfusion
Explanation
Dengue fever follows three phases: febrile (days 1–3), critical (days 4–6), and recovery (days 7–8). During the critical phase, plasma leakage into third spaces (due to increased vascular permeability) causes hemoconcentration, pleural effusions, and ascites. Clinical warning signs include abdominal pain, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy, liver enlargement >2 cm, and rising hematocrit with rapid platelet fall. Management is careful IV fluid therapy (isotonic crystalloids; avoid excessive fluids). FFP is not indicated for thrombocytopenia without active significant bleeding. Platelet transfusions are reserved for <10,000/mm³ or active severe hemorrhage.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
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Written and medically reviewed by the StethoPrep medical team.