Epidemiology


Etiology


There are 4 dengue virus serotypes, and secondary infection with a different viral serotype is common and is usually associated with more severe illness.

Pathophysiology


Clinical features


  • Dengue fever (nonhemorrhagic)
    • Flu-like febrile illness with marked myalgia &/or arthralgia
      • Often referred to as “break-bone fever”
    • Diffuse maculopapular rash
    • Retroorbital pain
    • Leukopenia
  • Severe dengue (hemorrhagic, formally called dengue hemorrhagic fever or DHF)
    • DHF typically occurs as a result of an antibody-dependent reaction in patients who are reinfected with a different serotype
    • Generally develops as the initial fever subsides (∼ 1 week after onset)
    • Temperature change: ranges from hypothermia to a second spike in fever
    • Severe hemorrhagic manifestations (e.g., petechiae, ecchymoses, purpura, hematemesis, melena) due to thrombocytopenia (&lt 100,000/mm3)
    • Severely increased vascular permeability
      • Pleural effusion, respiratory distress
      • Ascites, abdominal pain
      • Severe ↑ or ↓ Hct
    • Positive tourniquet test (petechiae after sphygmomanometer cuff inflation for 5 min)
    • Spontaneous bleeding → shock

Diagnostics


Treatment