clinical features

Last reviewed 01/2018

Infection by any of the four dengue serotypes may lead to symptomatic infections or asymptomatic seroconversion (1)

  • asymptomatic infection
    • around half of patients with dengue infection have no clinical signs or symptoms of disease.
  • symptomatic infection
    • is a systemic and dynamic disease with a wide clinical spectrum that includes both severe and non severe clinical manifestations
    • severe disease usually follows three phases – febrile, critical and recovery
    • the severity of the disease usually becomes apparent around defervescence e.g. – during the transition from the febrile to afebrile phase (around the time of the onset of the critical phase)
    • can be divided into
      • undifferentiated fever
        • presents with fever and mild non-specific symptoms which may mimic other viral infections
        • do not meet case definition criteria for DF
        • typically young children or those experiencing their first infection (may also occur during a secondary infection)
        • usually recover fully without need for hospital care
      • classic dengue fever (DF)
      • more severe forms of the disease - haemorrhagic fever (DHF) and dengue shock syndrome (DSS) (1,2)

Abrupt onset of symptoms occur after an incubation period of 3-14 days (average 7 days).

  • fever
    • characteristic feature of the infection with high spikes of 39.4-40.5°C
    • maybe seen as biphasic with a fluctuating body temperatures or as low grade fever over five to seven days
    • may result in febrile seizures or delirium in young children
  • aches and pains
    • frequent backache, arthralgia, myalgia, and bone pain are common
    • constant headache seen towards the front of the head is typical which resolves within a few days
    • severe retro-orbital pain with eye movement or with a little pressure applied to the eyeball
  • gastrointestinal symptoms
    • anorexia, nausea or vomiting, epigastric discomfort or pain
    • lack of appetite or changes to taste sensation
  • lethargy or restlessness
  • collapse, or dizziness
  • upper respiratory tract symptoms such as cough, sore throat may atypically occur in mild infection (3)

Signs present in dengue infection are:

  • diffuse skin flushing of the face, neck, and chest
    • on day 3 or 4 of the fever, skin flushing may progress into  maculopapular or rubelliform rash
    • blanching of the skin may be present
    • rash fades with time and appear as pallid areas during the convalescent phase
  • haemorrhagic signs
    • petechiae, purpura
    • positive tourniquet test
      • record patient’s blood pressure
      • inflate the cuff to a point midway between SBP and DBP and maintain for 5 minutes
      • the test is positive when  10 or more petechiae per 1 square inch appear in the forearm (below antecubital fossa)
      • epistaxis, gingival bleeding, haematemesis, melaena, vaginal bleeding (in women of childbearing age), or bleeding from a venepuncture site indicates major haemorrhages
    • these signs may be observed in either dengue fever or dengue haemorrhagic fever.
  • heaptomegaly
  • ascites, postural dizziness, or pleural effusion – indicates plasma leakage seen in dengue haemorrhagic fever
  • circulatory collapse – supports a diagnosis of dengue shock syndrome
    • cold clammy skin
    • rapid and weak pulse with narrowing of pulse pressure <20 mm Hg with decreased diastolic pressure
    • postural drop of blood pressure >20 mm Hg
    • capillary refill time greater than three seconds
    • reduced urine output (3)

Reference:

Related pages:

clinical features of viral haemorrhagic fevers