A 7-year-old boy from Chennai presents with fever for 5 days, severe myalgia, and headache. On examination, he has a petechial rash on the trunk and a positive tourniquet test. His platelet count is 85,000/μL, haemoglobin 14 g/dL, and haematocrit 38%. Dengue serology (IgM) is positive. His blood pressure is 98/62 mmHg, heart rate 110/min, and capillary refill time is 2 seconds. What is the most appropriate immediate management?

Explanation

## Clinical Recognition of Dengue Haemorrhagic Fever (DHF) This child presents with **dengue fever progressing to DHF Grade I** (warning signs: thrombocytopenia <100,000/μL + haemoconcentration + positive tourniquet test + petechial rash). **Key Point:** The hallmark of DHF is plasma leakage, not bleeding per se. Management focuses on fluid resuscitation to prevent hypovolaemic shock, not prophylactic transfusions. ### Management Principles in DHF | Feature | Management | |---------|-------------| | **Fluid resuscitation** | Isotonic crystalloid (normal saline or Ringer's lactate) at 5–10 mL/kg/h, titrated to urine output ≥0.5 mL/kg/h | | **Monitoring** | Serial vital signs, haematocrit, platelet count every 6–12 h during critical phase | | **Platelet transfusion** | Reserved for spontaneous bleeding (GI bleed, intracranial bleed) or platelet <10,000/μL with bleeding risk | | **Antibiotics** | NOT indicated unless secondary bacterial infection suspected | | **Mechanical support** | Only if frank shock unresponsive to fluids or respiratory failure | **High-Yield:** Prophylactic platelet transfusion is **contraindicated** — it does not prevent bleeding and may worsen plasma leakage by increasing intravascular volume. **Clinical Pearl:** Rising haematocrit (>20% above baseline) in the presence of falling platelets is the red flag for plasma leakage and signals entry into the critical phase (days 3–7 of illness). **Mnemonic — DHF Management (FLUID):** - **F**luids: isotonic crystalloid, titrate to urine output - **L**ab: serial haematocrit, platelet count - **U**rgent monitoring: vital signs q4–6h - **I**ntervention: transfuse only if spontaneous bleeding - **D**ischarge: when afebrile ≥48 h, platelets rising, haematocrit stable ### Why This Child Does NOT Need Immediate Transfusion - Platelet count 85,000/μL is above the critical threshold (10,000/μL). - No evidence of spontaneous bleeding (petechiae ≠ active bleeding). - Vital signs show early shock signs (tachycardia, borderline BP) — fluid resuscitation is the priority. - Transfusion in the absence of bleeding worsens plasma leakage and increases risk of fluid overload. [cite:Park 26e Ch 7 (Dengue)]