1. Dengue Fever Haemoconcentration (Hct ↑ by >20% or Hct >45%)
+
HypoNa < 5 mEq/L
Flavivirus – 4 different serotypes ± Haemorrhagic manifestations (petechia, ecchymosis, epistaxis, gum
Vector: Aedes aegypti & Aedes albopictus mosquitoes bleeding, hemetemesis, melena, retinal h’age)
Incubation period : 3 - 10 days (usually 4 - 6 days). hepatic enlargement & tenderness – poor prognostic signs
Infectious period : Within 5 days from onset of the illness. Pleural effusion, hypoalbuminemia, swollen fingers or pedal edema secondary
Notifiable disease to increased capillary permeability
Pathophysiology: Encephalopathy with N CSF or neurological disturbances (eg seizures, cranial
o Increased capillary permeability nerve signs, coma)
o
rd
Diffused capillary leakage of plasma (3 space fluid loss) Acute liver failure: a/w altered mental state, abN neurological signs
o Haemoconcentration (hyperreflexia), brain oedema, severe hemorrhage, pul. Oedema, renal failure
o ± shock & superimposed infection.
WHO classification
Symptoms & signs Grade I Fever, constitutional symptoms, positive tourniquet test
Prodromal Malaise & headaches for 2 days Grade II Grade I + spontaneous bleeding
Acute onset Fever (2-7 days) Scleral injection Grade III Grade II + haemodynamic instability w mental confusion
Backache Pain on eye movt Grade IV Grade III + shock
Arthralgia, myalgia Lacrimation * cases are accompanied with thrombocytopaenia & haemoconcentration
Generalized pain, abdo pain Headache **Grades III & IV denote Dengue Shock Syndrome (DSS)
Lymphadenopathy N/V
LOA Relative bradycardia
Bleeding gums depression
th th
Fever ‘saddle-back’ fever with break on 4 -5 day
or continuous fever Presentations
usually lasts 7 days Persistent fever > 3 days recalcitrant to Rx
Rash initially transient macular rash Severe backaches, headache, myalgia
maculopapular scarlet morbilliform rash Rash: maculopapular or flush; petechial with islands of sparing
spreads centrifugally Abdominal symptoms: N/V, epigastric pain, diarrhea (may be mistaken for
sparing of palms & soles gastroenteritis or viral gastritis)
Clinical manifestations
1) Dengue Fever Diagnostic Criteria
Characterized by fever, thrombocytopenia, MP petechial rash • Abrupt onset of high fever, continuous and lasting 2 - 7 days, headache, myalgia
Dz severity not related to plt count. Plt usu decrease just after fever resolves and arthralgia.
around day 5 to 7 • Haemorrhagic manifestations including any of the following:
Otherwise similar to other viral fevers - Positive tourniquet test
Pruritus over palms usually occur later - Petechiae, purpura, ecchymosis
- Epistaxis, gum bleeding
2) Dengue Haemorrhagic Shock (DHS) - Haematemesis and/or melaena
Usually due to reinfection by another serotype, or in rare cases, a/w infection • Enlargement of liver.
of infants with dengue antibodies from mothers
3 • 2
Thrombocytopenia (100,000/mm or less).
Thrombocytopenia (<100,000 / mm )
• Haemoconcentration (haematocrit increased by 20% or more)

2. Correct electrolytes imbalances & metabolic acidosis
Dx of DHF: The presence of the first two clinical criteria plus thrombocytopenia and Once stabilized, prevent pulmonary oedema by careful IV fluid administration
haemoconcentration Avoid salicylates for pain relief due to risk of bleeding diathesis and association of
dengue with Reye’s syndrome. Avoid hepatotoxic drugs and long acting sedatives
Dx of DSS:
• All the above criteria, plus Disposition
• Shock as manifested by rapid and weak pulse with narrowing of pulse pressure Grade I responding to oral fluid hydration w no Cx – home
(<20 mmHg, regardless of pressure levels) or hypotension with cold, clammy skin Admit all other PTs for IV fluid therapy (significant dehydration, spontaneous
and restlessness. bleeding, bleeding tendency, sever thrombocytopenia, extremes of age,
concomitant illnesses)
Those with platelet counts between 100-140K can be discharge but should return
Investigations for f/u serial FBC until platelet normalizes
FBC Haemconcentration
Leucopaenia (leukocytosis & neutrophilia Complications
excludes dengue – consider bacterial DHF – Haemorrhagic tendencies
rd
infxns) DSS – 3 space fluid loss, hemorrhage, myocarditis (rare)
3
Thrombocytopaenia (<100K / mm ) Abdominal pain – due to pancreatitis, hepatitis or retroperitoneal bleed
PT/aPTT Lungs – ARDS, pleural effusion
+
U/E/Cr hypoNa
LFT Abnormal liver enzymes (usu AST>ALT)
Dengue serology For IgM, which usually develops on day 5
30% will be negative at day 5
PCR if rapid dx required (before 5 days)
Management
Monitoring: vital signs, haemoconcentration, daily platelets counts (when plt <100K,
until upward trend is seen), coagulation profile
Fluid replacement: N/S or Ringer solution (avoid over-hydration in DHF. Might ppt pul.
oedema)
Correct electrolytes imbalances
Paracetamol for fever
Anti-histamines for pruritus
No IM injections
Complete rest in bed if platelet <50K due to risk of bleeding from accidental trauma.
Digitally signed by DR WANA HLA SHWE
Plt transfusion when plt <20K. (Risk of spontaneous bleeding) DN: cn=DR WANA HLA SHWE, c=MY,
Note: thrombocytopenia usually worsens AFTER fever resolves o=UCSI University, School of Medicine, KT-
Notifiable disease Campus, Terengganu, ou=Internal Medicine
Group, email=wunna.hlashwe@gmail.com
Reason: This document is for UCSI year 4
Acute Mx of DSS students.
Date: 2009.02.24 10:41:46 +08'00'
Monitoring: vital signs, haemoconcentration, daily platelets counts (until upward trend
is seen), coagulation profile
Oxygen therapy
Fluid replacement: N/S or Ringer solution