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Dengue Fever, Emergency Medicine

Basics

Description

- Dengue fever occurs secondary to dengue viral infection. - Most prevalent mosquito-borne viral infection. - Poorly understood immunopathologic response causes dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). - DHF and DSS usually occur in patients with previous exposure to dengue virus. - Hemorrhagic manifestations occur after defervescence of fever. - Vascular permeability increases. - Plasma extravasates into extravascular space, including pleural and abdominal cavities. - Bleeding tendency - Shock may ensue. - Disseminated intravascular coagulation (DIC) may develop. - Dengue fever, DHF, and DSS are all self-limited. - World Health Organization-required criteria for the diagnosis of DHF: - Fever - Bleeding evidenced by one of the following: Positive tourniquet test, petechiae, ecchymosis, purpura, GI tract bleeding, injection site bleeding - Increased vascular permeability and plasma leakage as evidenced by an elevated hematocrit (>20%), decreased hematocrit >20% after volume replacement or pleural effusions, ascites or hypoproteinemia - Thrombocytopenia (<100,000/mm3)

- World Health Organization-required criteria for diagnosis of DSS: - All 4 criteria of DHF + - Rapid and weak pulse - Narrow pulse pressure or hypotension for age - Cold, clammy skin - Restlessness

- Fever: - Abrupt in onset rising to 39 °C or higher - 2-7 days duration - Biphasic ("saddleback") curve, returning to almost normal after 2-7 days - Associated with frontal or retro-orbital headache

  • Dengue fever occurs secondary to dengue viral infection.
  • Most prevalent mosquito-borne viral infection.
  • Poorly understood immunopathologic response causes dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).
  • DHF and DSS usually occur in patients with previous exposure to dengue virus.
  • Hemorrhagic manifestations occur after defervescence of fever.
  • Vascular permeability increases.
  • Plasma extravasates into extravascular space, including pleural and abdominal cavities.
  • Bleeding tendency
  • Shock may ensue.
  • Disseminated intravascular coagulation (DIC) may develop.
  • Dengue fever, DHF, and DSS are all self-limited.
  • World Health Organization-required criteria for the diagnosis of DHF:FeverBleeding evidenced by one of the following: Positive tourniquet test, petechiae, ecchymosis, purpura, GI tract bleeding, injection site bleedingIncreased vascular permeability and plasma leakage as evidenced by an elevated hematocrit (>20%), decreased hematocrit >20% after volume replacement or pleural effusions, ascites or hypoproteinemiaThrombocytopenia (<100,000/mm3)
  • World Health Organization-required criteria for diagnosis of DSS:All 4 criteria of DHF +Rapid and weak pulseNarrow pulse pressure or hypotension for ageCold, clammy skinRestlessness

Etiology

  • Occurs in tropical and subtropical regions: Asia, Africa, Central and South America, and the Caribbean
  • Caused by dengue virus serotypes 1-4
  • Transmitted by mosquitoes: Aedes aegypti and Aedes albopictus
  • Incubation period of 3-14 days
  • There is only transient and poor cross protection among the 4 serotypes

Diagnosis

Signs and Symptoms

  • Fever:Abrupt in onset rising to 39 °C or higher2-7 days durationBiphasic ("saddleback") curve, returning to almost normal after 2-7 daysAssociated with frontal or retro-orbital headache
  • Rash:Generalized maculopapular rash occurs with onset of fever in 50% of patients.After 3-4 days, rash becomes diffusely erythematous.Faded areas appear.Areas of desquamation may appear.After defervescence of fever, scattered petechiae may develop over trunk, extensor surfaces of limbs, and axillae.Palms and soles spared
  • Musculoskeletal:Arthralgias and myalgias after onset of feverSevere lumbar back pain
  • GI:AnorexiaNausea and vomitingAbdominal pain (sometimes severe)Altered tasteHepatomegaly/ascitesGI bleeding
  • Miscellaneous:EpistaxisGingival bleedingHemoptysisHypotensionNarrowed pulse pressure (<20 mm Hg)Retro-orbital pain

Essential Workup

  • Primarily a clinical diagnosis
  • Suspect in endemic areas
  • Suspect in patients with history of travel

Diagnosis Tests & Interpretation

Lab

  • CBC:ThrombocytopeniaElevated hematocrit
  • Electrolytes, BUN, creatinine:
  • Liver function tests:Elevated aspartate transaminase (AST; or serum glutamic-oxaloacetic transaminase [SGOT])
  • Coagulation profiles:Prolonged INR, prothrombin time (PT), and partial thromboplastin time (PTT)Low fibrinogen:Virus isolation or detection of dengue virus-specific antibodies (available in only a few labs) through hemagglutination inhibition (HI) assay

Imaging

CXR:

Diagnostic Procedures/Surgery

Tourniquet test:

  • Inflate BP cuff to median BP in patients extremity.
  • Test is positive when 3 or more petechiae appear per square centimeter.

Differential Diagnosis

  • Viral illness, nonspecific
  • Influenza
  • Rubella
  • Measles
  • Malaria
  • Rocky Mountain spotted fever
  • Typhoid
  • Kawasaki disease
  • Scarlet fever
  • Erythema infectiosum
  • Mononucleosis
  • Roseola infantum
  • Secondary syphilis
  • Enterovirus
  • West Nile virus
  • HIV
  • Leptospirosis
  • Chikungunya fever
  • Toxic shock syndrome
  • Hepatitis
  • Appendicitis
  • Meningitis

Treatment

Initial Stabilization/Therapy

  • IV access
  • IV crystalloids for hypotension
  • O2 and monitor for unstable patients

Ed Treatment/Procedures

  • Treatment is supportive.
  • IV fluids
  • Acetaminophen (Tylenol) for fever
  • Analgesics for pain
  • Platelet transfusion for severe thrombocytopenia
  • DIC therapy, if necessary
  • Neonatal dengue can occur by vertical transmission if mother infected 0-8 days before delivery:Infants may develop DHF or DSS because of passive maternal immunity.
  • DHF and DSS most common in children 7-12 yr of age

Follow-Up

Disposition

Admission Criteria

  • ICU admission for the following:HypotensionDICThrombocytopeniaHemoconcentration
  • Regular admission for the following:15 yr of age or youngerAll patients with previous dengue exposureAny patient where close follow-up is not available

Discharge Criteria

  • Close follow-up guaranteed
  • Tolerating PO
  • Pain controlled

Pearls and Pitfalls

  • Consider dengue in patients presenting with fever and rash who recently traveled to endemic regions.
  • Chikungunya fever is an emerging infectious disease also seen in travelers and must be considered in the differential:

Additional Reading

  • Halstead SB: Dengue. Lancet. 2007;370:1644-1652.
  • Ist şriz RE, Gubler DJ, Brea del Castillo J. Dengue and dengue hemorrhagic fever in Latin America and the Caribbean. Infect Dis Clin North Am. 2000;14(1):121-140.
  • Pincus LB, Grossman ME, Fox LP. The exanthem of dengue fever: Clinical features of two US tourists traveling abroad. J Am Acad Dermatol. 2008;58(2):308-316.
  • Simmons CP, Farrar JJ, Nguyen vV, et al. Dengue. N Engl J Med. 2012;366:1423-1432.
  • Wilder-Smith A, Schwartz E: Dengue in travelers. N Engl J Med. 2005;353:924-932.

Codes

ICD9

061 Dengue

ICD10

A90 Dengue fever [classical dengue]

SNOMED

  • 38362002 Dengue (disorder)
  • 20927009 Dengue hemorrhagic fever (disorder)
  • 409671005 Dengue shock syndrome