Dengue Fever

General Medicine

Acute febrile illness due to dengue virus (DENV 1–4) transmitted by Aedes mosquito; spectrum from undifferentiated fever to severe dengue.

History taking

  • Sudden high fever (3–7 d), retro-orbital pain, myalgia, arthralgia, headache
  • Rash on day 3–5, nausea, vomiting
  • Warning signs: severe abdominal pain, persistent vomiting, mucosal bleed, lethargy, restlessness

Examination

  • Flushed face, tourniquet test, petechiae
  • Volume status — capillary refill, postural BP, pulse pressure
  • Hepatomegaly, free fluid (ascites, pleural effusion)

Red flags

  • Warning signs (above)
  • Severe plasma leakage (shock, respiratory distress)
  • Severe bleeding, organ involvement (AST/ALT >1000, encephalopathy)

Differential diagnosis

  • Chikungunya, malaria, leptospirosis, scrub typhus, viral fever, COVID-19

Recommended investigations

  • CBC daily — falling platelets, rising haematocrit
  • NS1 antigen (day 1–5), IgM/IgG (after day 5)
  • LFT, RFT, electrolytes, coagulation, ABG if severe
  • USG abdomen / chest for plasma leakage

Diagnosis

  • WHO 2009: dengue without warning signs / with warning signs / severe dengue

Initial treatment / management

  • Group A (no warning): oral fluids 2.5–3 L/d, paracetamol, daily CBC
  • Group B (warning signs): IV crystalloid (RL) 5–7 mL/kg/h, titrate by HCT and urine output
  • Group C (severe): aggressive resuscitation per WHO algorithm; ICU
  • Avoid NSAIDs, aspirin, IM injections

Prescription examples

  • Tab Paracetamol 500–1000 mg PO 6 hourly (max 4 g/d)
  • Oral fluid (ORS, soups, fresh juice) — 2.5 L/day
  • Strictly avoid Aspirin, Ibuprofen, Diclofenac

Follow-up advice

  • Daily CBC during febrile phase; admit if warning signs or platelets <50k
  • Critical phase day 4–6 — monitor closely for plasma leak

Patient counselling

  • Mosquito source reduction, repellents, full-sleeve clothing
  • Recognise warning signs and seek care immediately

Referral criteria

  • Warning signs, severe dengue, pregnancy, infants
  • Co-morbid (CKD, IHD), elderly, immunocompromised

Clinical pearls

  • Defervescence (day 3–6) heralds the critical phase — vigilance for shock
  • Platelet transfusion only if active bleed or count <10k
  • Fluid overload is the leading iatrogenic cause of death in severe dengue

References

  • WHO Dengue Guidelines for Diagnosis, Treatment, Prevention 2009 / 2023 addendum
  • National Guidelines for Clinical Management of Dengue NVBDCP 2014

Educational outpatient guide — verify against local guidelines before clinical use.

WardRound

WardRound

Clinical Decisions in Seconds