A summary of CDC's clinical features page for healthcare providers.
- About 1 in 4 dengue virus infections cause symptoms.
- About 1 in 20 patients with dengue go on to severe dengue, which is life-threatening.
- There are four dengue viruses (DENV), so a person can be infected several times in a lifetime. Infection with one type generally gives lifelong protection against that type, but only short-lived protection — several months to years — against the others.
Presentation
Dengue starts abruptly after an incubation period of typically 5–7 days and passes through three phases: febrile, critical and recovery.
Early findings are nonspecific, so a high index of suspicion is needed: recognising early signs of shock and promptly starting intensive supportive care with intravenous fluids can cut the risk of death in severe dengue to under 0.5%.
Common laboratory findings: leukopenia, thrombocytopenia, hyponatraemia, raised aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and a normal erythrocyte sedimentation rate (ESR).
Febrile phase
- Fever usually lasts 2–7 days and can be biphasic.
- Other features may include severe headache, pain behind the eyes, muscle and joint pain, a macular or maculopapular rash, and minor bleeding — petechiae, ecchymosis, purpura, nosebleeds, bleeding gums, blood in the urine, or a positive tourniquet test.
- Some patients have an injected oropharynx and facial redness in the first 24–48 hours.
- Warning signs of progression to severe dengue usually appear late in this phase, around defervescence (when the fever falls).
Critical phase
- Begins at defervescence and usually lasts 24–48 hours.
- Most patients improve, but those with substantial plasma leakage can develop severe dengue within hours.
- At first the body compensates and circulation holds up, but pulse pressure narrows as diastolic pressure rises.
- Severe leakage may bring pleural effusions, ascites, hypoproteinaemia or haemoconcentration.
- Patients may look well despite early shock. Once hypotension sets in, systolic pressure falls fast, and irreversible shock and death may follow despite resuscitation.
- Severe bleeding — haematemesis, haematochezia, menorrhagia — can occur, especially after prolonged shock. Hepatitis, myocarditis, pancreatitis and encephalitis are uncommon.
Recovery phase
- As leakage subsides, the patient reabsorbs leaked intravenous fluid and pleural and abdominal effusions.
- Circulation stabilises (bradycardia may occur) and diuresis follows. Haematocrit stabilises, or may fall as reabsorbed fluid dilutes the blood; the white cell count usually rises first, then platelets recover.
- The recovery-phase rash may peel and itch.
The WHO 2009 classification
| Category | Definition |
|---|---|
| Dengue | fever plus two or more clinical findings in someone who lives in, or has been in the last 14 days to, an area where dengue is endemic. Findings: nausea, vomiting, rash, aches and pains, a positive tourniquet test, leukopenia, or any warning sign |
| Warning signs | abdominal pain or tenderness, persistent vomiting, clinical fluid accumulation, mucosal bleeding, lethargy, restlessness, liver enlargement. Patients with warning signs need close monitoring, as they are more likely to progress |
| Severe dengue | dengue with severe plasma leakage causing shock or fluid accumulation with respiratory distress; severe bleeding; or severe organ impairment, such as hepatitis (transaminases of 1,000 IU/L or more), impaired consciousness or heart impairment |
Sources
- Centers for Disease Control and Prevention, "Clinical Features of Dengue." https://www.cdc.gov/dengue/hcp/clinical-signs/index.html
- The classification is the World Health Organization's, from 2009.
- Words on this page from people and organisations outside the federal government are paraphrased; rewritten in hubnx's own words.
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Licence: CC0 1.0 (public domain) · Adapted from www.cdc.gov
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