Dengue Management

Overview

WHO 2009 / Updated Classification

Clinical Phases

1. Febrile phase (days 1-3): Abrupt-onset high fever, severe headache, retro-orbital pain, myalgia/arthralgia ("breakbone fever"), facial flushing, macular/maculopapular rash, leukopenia, petechiae.
2. Critical phase (days 4-6, around defervescence): Plasma leakage occurs over a 24-48 hour window. Hematocrit rises (hemoconcentration), platelets fall rapidly. This is the most dangerous window - patients may deteriorate suddenly into shock. Warning signs appear here.
3. Convalescent phase (days 7-10): Plasma is reabsorbed. Risk of fluid overload rises; hematocrit drops dilutionally. Bradycardia, rash, and pruritus are common.

Diagnosis

Management by Severity

Group A - Dengue Without Warning Signs (Outpatient)

• Oral rehydration (encourage fluids: water, ORS, coconut water, fresh juices)
• Paracetamol (acetaminophen) for fever and pain - the only safe antipyretic
• AVOID: aspirin, NSAIDs (ibuprofen), salicylates - increase bleeding risk and can precipitate Reye syndrome in children
• Return precautions: instruct patient/family on warning signs
• Daily monitoring for warning signs during the critical phase (days 3-6)
• Stable patients can be discharged and followed up daily

Group B - Dengue With Warning Signs (Hospital Admission)

• IV fluid therapy is the cornerstone:
  • Start with isotonic crystalloid (0.9% NaCl or lactated Ringer's): 5-7 mL/kg/hour for 1-2 hours, then reduce to 3-5 mL/kg/hr, then 2-3 mL/kg/hr
  • Titrate fluids to maintain urine output 0.5-1 mL/kg/hr
• Monitor vitals, urine output, hematocrit every 1-4 hours
• Serial CBC: hematocrit is the key guide - rising Hct = ongoing leak; falling Hct without clinical improvement = bleeding
• Platelet transfusion: generally reserved for active significant bleeding or platelet <10,000/µL (prophylactic transfusion in dengue is controversial and generally not recommended)
• Strict fluid balance charting

Group C - Severe Dengue / Dengue Shock Syndrome (ICU-level care)

• Immediate IV fluid bolus: isotonic crystalloid 10-20 mL/kg over 15-30 minutes
• Reassess frequently; repeat bolus if hemodynamics do not improve
• If not responding after 2-3 crystalloid boluses: switch to colloids (dextran-40, gelatin, or albumin) - used for refractory shock
• Blood products:
  • Packed red cells for hemodynamic compromise with significant bleeding or Hct drop
  • Fresh frozen plasma / cryoprecipitate for coagulopathy with active bleeding
  • Platelet transfusion for active severe bleeding + low platelets
• Avoid fluid overload - watch for pulmonary edema, especially during reabsorption phase
• Inotropes for myocardial dysfunction if needed
• Steroids: multiple low-quality trials have been done - current evidence is inconclusive; steroids are NOT routinely recommended for severe dengue

Special Situations

Dengue in Pregnancy

• Higher risk of vertical transmission (approximately 20%; higher near delivery)
• Risk of preterm birth, fetal distress, neonatal dengue
• Fluid management is more complex due to physiological changes; avoid fluid overload
• Neonatal dengue can present with thrombocytopenia, fever, or hepatitis

Dengue-related Organ Involvement

• Hepatitis: AST/ALT elevation is common; fulminant hepatic failure is rare but possible
• Encephalitis/ADEM: rare neurological complications
• Myocarditis: bradycardia or arrhythmia during acute phase
• Hemophagocytic lymphohistiocytosis (HLH): rare but associated with significant mortality (identified in a 2024 meta-analysis)
• Acute kidney injury: particularly in DHF/DSS; monitor renal function

The Reabsorption Phase (Days 7-10)

• Plasma leaks back into circulation
• Continuing IV fluids at this stage causes fluid overload / pulmonary edema
• If hematocrit drops without clinical deterioration, reduce IV fluids, not increase them
• Diuretics (furosemide) may be needed for fluid overload

Platelet Monitoring Guide

Differential Diagnosis

Disposition Summary

Vaccination (Prevention)

• Dengvaxia (CYD-TDV): 3-dose schedule (0, 6, 12 months); approved for ages 9-45 years who have documented prior dengue infection (seropositive individuals only). Seronegative recipients face increased risk of severe dengue on subsequent infection - seroscreen before vaccination is mandatory.
• TAK-003 (Qdenga): A newer live-attenuated tetravalent vaccine; approved in several countries including EU, UK, and Brazil; does not require pre-vaccination seroscreening.
• Vector control (elimination of standing water, insecticides, insect repellents, window screens) remains the primary public health strategy.

Key "Do Not Miss" Points

1. Defervescence ≠ improvement - the critical phase begins at defervescence; this is when deterioration happens
2. Never give aspirin or NSAIDs for fever or pain in suspected dengue
3. Rising hematocrit is the earliest sign of plasma leak - check serial CBCs
4. Platelet count alone does not guide fluid therapy - hematocrit and hemodynamics do
5. Fluid overload kills too - stop fluids once the patient stabilizes; watch the reabsorption phase

2025 Update: WHO published new guidelines in July 2025 covering clinical management of dengue alongside other arboviral diseases (chikungunya, Zika, yellow fever), the first unified WHO guidance covering all four diseases - WHO arboviral guidelines 2025.