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
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 higher
- 2-7 days duration
- Biphasic ("saddleback") curve, returning to almost normal after 2-7 days
- Associated 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 fever
- Severe lumbar back pain
- GI:
- Anorexia
- Nausea and vomiting
- Abdominal pain (sometimes severe)
- Altered taste
- Hepatomegaly/ascites
- GI bleeding
- Miscellaneous:
- Epistaxis
- Gingival bleeding
- Hemoptysis
- Hypotension
- Narrowed 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:
- Thrombocytopenia
- Elevated 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:
- Hypotension
- DIC
- Thrombocytopenia
- Hemoconcentration
- Regular admission for the following:
- 15 yr of age or younger
- All patients with previous dengue exposure
- Any 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