SOAP Notes for Dengue Fever
A comprehensive SOAP note for dengue must include specific epidemiologic risk factors, characteristic symptom patterns, daily laboratory monitoring parameters, warning signs assessment, and detailed fluid management plans, as these elements directly guide risk stratification and prevent progression to shock.
Subjective
Chief Complaint and History of Present Illness
- Document fever onset and duration with specific attention to the 4-8 day incubation period after mosquito exposure 1, 2
- Record characteristic symptom triad: frontal headache, retro-orbital pain, and severe myalgias/arthralgias ("breakbone fever") 2, 3
- Note presence of rash and its timing in relation to fever 1, 4
- Assess for warning signs that indicate progression to severe dengue: persistent vomiting (inability to maintain oral hydration), severe abdominal pain or tenderness, clinical fluid accumulation (ascites, pleural effusion), mucosal bleeding, lethargy or restlessness 1, 2, 5
Epidemiologic History
- Travel history to tropical/subtropical regions within the past 2 weeks, specifically areas with active dengue transmission 2, 3
- Exposure to day-biting Aedes mosquitoes (Aedes aegypti primarily) 1, 2
- For pregnant women: Document gestational age and any exposure to both dengue and Zika endemic areas, as concurrent testing is mandatory regardless of outbreak patterns 6, 2, 5
Past Medical History
- Previous dengue infections (increases risk of severe dengue with heterotypic infection) 4, 7
- Vaccination history for yellow fever, Japanese encephalitis, and tick-borne encephalitis to anticipate serologic cross-reactivity 1
- Pregnancy status (requires different diagnostic and monitoring approach) 6, 5
Objective
Vital Signs and Physical Examination
- Temperature pattern: Document biphasic fever characteristic of dengue 4, 7
- Hemodynamic parameters: Blood pressure, pulse pressure (narrow pulse pressure ≤20 mmHg indicates shock), heart rate, capillary refill time 1, 5
- Signs of plasma leakage: Ascites, pleural effusion, peripheral edema 1, 8
- Bleeding manifestations: Petechiae, purpura, mucosal bleeding, positive tourniquet test 1, 8
- Mental status: Lethargy, restlessness, or altered consciousness 1, 2
Laboratory Findings (Daily Monitoring Required)
- Complete blood count with differential performed daily during critical phase (days 3-7 of illness) 1, 2, 5:
- Platelet count: Thrombocytopenia ≤100,000/mm³ defines dengue hemorrhagic fever; rapidly declining platelets warrant hospitalization 1, 2
- Hematocrit: Rising hematocrit (≥20% increase from baseline) indicates plasma leakage and requires aggressive fluid management 1, 2, 5
- White blood cell count: Leukopenia is frequent during febrile phase 2
Diagnostic Testing
- For symptoms ≤7 days: Dengue PCR/NAAT on serum (viral RNA detectable 2 days before to 7 days after symptom onset) 1, 2, 5
- For symptoms >7 days or negative NAAT: IgM capture ELISA on serum (IgM develops during first week and persists for months) 1, 2, 5
- For pregnant women: Concurrent dengue and Zika virus NAATs on serum AND urine, plus IgM testing for both viruses, collected within 12 weeks of symptom onset 6, 2, 5
- Confirmatory testing: Plaque reduction neutralization test (PRNT) if IgM positive but NAAT negative, to distinguish dengue from Zika and other flaviviruses 6
Critical caveat: Negative NAAT collected >7 days after onset does not rule out infection due to viral clearance; IgM testing is required 6. Conversely, negative IgM collected ≤7 days after onset may reflect testing before antibody development 6.
Assessment
Risk Stratification (Determines Inpatient vs Outpatient Management)
Hospitalization criteria 1, 5:
- Severe plasma leakage, severe bleeding, or organ failure
- Dengue shock syndrome (narrow pulse pressure ≤20 mmHg or hypotension)
- Persistent vomiting preventing oral hydration
- Rapidly declining platelets or platelets ≤100,000/mm³ with rapid decline
- Rising hematocrit (>20% increase) with falling platelets
- Pregnancy with confirmed or suspected dengue
Outpatient management criteria 1:
- Platelet count >100,000/mm³ without rapid decline
- Stable hematocrit without hemoconcentration
- Adequate oral intake maintained
- No warning signs present
Disease Classification
- Probable dengue: Clinically compatible illness with appropriate epidemiologic exposure 1
- Dengue with warning signs: Presence of any warning signs listed above 1, 2
- Severe dengue/Dengue hemorrhagic fever: Thrombocytopenia ≤100,000/mm³ plus evidence of plasma leakage (rising hematocrit ≥20%) and/or bleeding manifestations 1, 2, 8
- Dengue shock syndrome: All criteria for DHF plus hypotension or narrow pulse pressure ≤20 mmHg 1, 5
Differential Diagnosis Considerations
- Zika virus: Requires concurrent testing in endemic areas, especially for pregnant women 6, 2, 5
- Other flaviviruses: Yellow fever, Japanese encephalitis (consider vaccination history) 1
- Secondary bacterial infection: Occurs in <10% of cases; do NOT prescribe empiric antibiotics without evidence of bacterial co-infection 5
Plan
Fluid Management (Cornerstone of Treatment)
For uncomplicated dengue without shock 1, 2, 5:
- Aggressive oral hydration exceeding 2500 mL daily using oral rehydration solutions
- Encourage frequent small volumes if nausea present
For dengue shock syndrome 1, 2, 5:
- Initial bolus: 20 mL/kg isotonic crystalloid over 5-10 minutes
- Immediate reassessment after bolus completion
- Additional boluses if inadequate response
- Colloid solutions (albumin, dextran) for severe shock with pulse pressure <10 mmHg when crystalloids insufficient 1, 5
Critical pitfall: Do not delay fluid resuscitation while awaiting laboratory confirmation in patients with signs of shock 5.
Pain and Fever Management
- Acetaminophen at standard doses is the ONLY recommended analgesic 1, 2, 5
- NEVER use aspirin or NSAIDs under any circumstances due to catastrophic bleeding risk with thrombocytopenia 1, 2, 5, 4
- For pregnant women: Acetaminophen remains the safest option 1, 5
- For children: Calculate acetaminophen dosing carefully based on weight 1
Monitoring Plan
- Daily CBC to track platelets, hematocrit, and WBC during critical phase (days 3-7) 1, 2, 5
- Daily assessment for warning signs: Persistent vomiting, abdominal pain, fluid accumulation, bleeding, mental status changes 1, 2, 5
- Continuous cardiac telemetry and pulse oximetry for dengue shock syndrome 1
- Urine output monitoring: Target >0.5 mL/kg/hour in adults 1, 5
Management of Complications
- Significant bleeding: Blood product transfusion as needed (NOT prophylactic platelet transfusion) 8
- Persistent tissue hypoperfusion: Vasopressors (dopamine or epinephrine) if adequate fluid resuscitation fails 1
- Secondary hemophagocytic lymphohistiocytosis: Consider steroids or IVIG if recognized 8
- Persistent fever with hemodynamic instability: Broaden coverage for secondary bacterial infection with blood/urine cultures and chest radiograph 1
Common pitfall: Do not change antibiotics or management based solely on persistent fever pattern without clinical deterioration or new findings 1, 5.
Discharge Criteria (All Must Be Met)
- Afebrile for ≥48 hours without antipyretics 1, 2, 5
- Resolution or significant improvement of symptoms 1, 5
- Stable hemodynamic parameters for ≥24 hours without support 1, 5
- Adequate oral intake maintained 1, 5
- Adequate urine output (>0.5 mL/kg/hour in adults) 1, 5
- Laboratory parameters returning to normal ranges 1, 5
Post-Discharge Instructions
- Monitor temperature twice daily and return if ≥38°C on two consecutive readings 1
- Return immediately for any warning signs: persistent vomiting, severe abdominal pain, bleeding, lethargy, restlessness 1
Special Population Considerations
- Mandatory hospitalization due to risk of maternal death, hemorrhage, preeclampsia, and vertical transmission
- Concurrent NAAT testing for both dengue and Zika on serum and urine
- Ongoing surveillance throughout pregnancy and infant follow-up after delivery for congenital infection and microcephaly
Reporting Requirements
- Dengue is a nationally notifiable condition and must be reported to state, territorial, or local health departments 5