What are the typical presenting signs of dengue fever in a healthy adult?

Presenting Signs of Dengue Fever

Dengue fever classically presents with acute onset of high fever accompanied by frontal headache, retro-orbital pain, severe myalgia and arthralgia (hence "breakbone fever"), and a characteristic macular rash that typically spares the face and extremities. 1, 2

Core Clinical Features

The typical presentation includes:

• Fever: High-grade fever with abrupt onset, occurring 4-8 days after mosquito exposure 3, 1
• Headache: Frontal headache is characteristic 1, 2
• Retro-orbital pain: Pain behind the eyes is a distinguishing feature 1, 2
• Severe myalgia and arthralgia: Muscle and joint pains are prominent, giving rise to the term "breakbone fever" 4, 5
• Rash: Macular rash similar to measles, typically sparing the face and extremities 4, 2

Additional Common Symptoms

Beyond the classic triad, patients frequently experience:

• Nausea and vomiting 5, 6
• Prostration and marked fatigue 2
• Leukopenia on laboratory testing 1

Hemorrhagic Manifestations

Even in uncomplicated dengue, minor bleeding signs may appear:

• Petechiae or purpura 2
• Epistaxis (nosebleeds) 7, 2
• Bleeding gums 2
• Positive tourniquet test 1

These hemorrhagic signs occur in a subset of patients but do not necessarily indicate progression to severe disease 2.

Critical Warning Signs

The following warning signs indicate potential progression to severe dengue and require immediate medical attention and close monitoring: 8

• Persistent vomiting 1, 8
• Severe abdominal pain or tenderness 8
• Clinical fluid accumulation (ascites, pleural effusion) 8
• Mucosal bleeding 1, 8
• Lethargy or restlessness 1, 8
• Hepatomegaly (>2 cm) 8
• Rising hematocrit with concurrent rapid decline in platelet count 1, 8

These warning signs typically appear around days 3-7 of illness, coinciding with defervescence, and their early recognition can reduce case-fatality rates to <0.5% 8.

Laboratory Findings

Key hematological abnormalities include:

• Thrombocytopenia: The absence of thrombocytopenia significantly reduces the probability of dengue 1
• Hemoconcentration: Rising hematocrit (>20% increase from baseline) indicates plasma leakage 1
• Leukopenia: Low white blood cell count is common 1

Diagnostic Timing Considerations

The incubation period is 4-8 days (range 3-14 days) after exposure 3, 1. For diagnostic testing, PCR/NAAT is most effective when performed on serum collected ≤7 days after symptom onset, while IgM capture ELISA becomes appropriate after 5-7 days of symptoms 1, 8.

Common Pitfalls

Never use aspirin or NSAIDs when dengue is suspected or cannot be excluded, as these medications significantly increase bleeding risk. 1 Acetaminophen is the only appropriate analgesic for fever and pain management 1.

The spectrum of illness ranges from mild self-limiting febrile illness to life-threatening dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), though severe forms are rare in travelers 3, 4. The key to preventing progression is recognizing warning signs early and ensuring adequate hydration and close monitoring 1, 8.