What are the typical symptoms and warning signs of dengue infection?

Symptoms of Dengue

Dengue presents with acute fever accompanied by headache, retro-orbital pain, myalgia, arthralgia, and often a characteristic rash, with an incubation period of 4-8 days after mosquito exposure. 1, 2

Classic Clinical Presentation

The typical dengue infection manifests as a systemic febrile illness with the following features:

• Fever is the hallmark symptom, typically lasting up to 7 days 3
• Severe headache with retro-orbital (behind the eyes) pain is characteristic and helps distinguish dengue from other febrile illnesses 1, 2
• Myalgia (muscle pain) and arthralgia (joint pain) are prominent, earning dengue the nickname "breakbone fever" due to the severity of musculoskeletal discomfort 4, 3
• Rash typically appears during days 3-7 of illness, often coinciding with defervescence (when fever subsides), and may be maculopapular or measles-like in appearance 5, 4, 3
• Nausea and vomiting are common gastrointestinal symptoms 1, 6
• Fatigue, abnormal taste sensation, and anorexia frequently accompany the acute illness 3

Warning Signs of Severe Disease

Critical warning signs that indicate potential progression to severe dengue requiring immediate medical attention include: 7

• Persistent vomiting (unable to tolerate oral fluids) 7, 2
• Abdominal pain or tenderness, particularly in the right upper quadrant 7
• Clinical fluid accumulation (ascites, pleural effusion) 7
• Mucosal bleeding (nose, gums, or other sites) 7
• Lethargy or restlessness (altered mental status) 7
• Hepatomegaly (enlarged liver) 7
• Rising hematocrit with concurrent thrombocytopenia (>20% increase from baseline with platelet count ≤100,000/mm³) 7, 2

These warning signs typically appear around day 3-7 of illness, during the critical phase when defervescence occurs. 7

Spectrum of Disease Severity

Dengue exists on a clinical spectrum: 1, 2

• Dengue without warning signs: Mild febrile illness with the classic symptoms described above, manageable as an outpatient with oral hydration 7, 2
• Dengue hemorrhagic fever (DHF): Characterized by minor or major bleeding phenomena, thrombocytopenia, and evidence of plasma leakage 7, 6
• Dengue shock syndrome (DSS): All DHF criteria plus hypotension (systolic BP <90 mmHg for >30 minutes) or narrow pulse pressure (<20 mmHg), with signs of end-organ hypoperfusion including cold/clammy extremities and capillary refill time ≥3 seconds 7

Key Clinical Pitfalls

• Absence of thrombocytopenia significantly reduces the probability of dengue, making it a useful rule-out finding 2
• Narrow pulse pressure (<20 mmHg) is an earlier and more sensitive indicator of dengue shock than absolute hypotension and should be monitored closely 7
• The majority of dengue infections (approximately 80%) remain mild, but around 1% progress to severe forms requiring hospitalization 3, 6
• Never use aspirin or NSAIDs when dengue is suspected due to increased bleeding risk; acetaminophen is the only safe analgesic option 2, 5

Diagnostic Considerations

Dengue should be suspected in any patient with fever plus at least one of the following symptoms—particularly with travel to or residence in endemic areas within the past 14 days: 2

• Nausea, vomiting, rash, headache, retro-orbital pain, myalgia, arthralgia, positive tourniquet test, or leukopenia 2
• The incubation period ranges from 3-14 days, with most cases presenting 4-8 days after exposure 1