Early symptoms of Dengue hemorrhagic fever are similar to those of Dengue fever, but after several days the patient becomes irritable, restless, and sweaty. These symptoms are followed by a shock-like state.

Bleeding may appear as pinpoint spots of blood on the skin (petechiae) and larger patches of blood under the skin (ecchymoses). Bleeding may occur from minor injuries.

Shock may cause death. If the patient survives, recovery begins after a one-day crisis period.

Early symptoms include the following:

• Fever
• Headache
• Muscle aches
• Joint aches
• Malaise
• Decreased appetite
• Vomiting

• Shock-like state
  • Sweaty (diaphoretic)
  • Cold clammy extremities
• Restlessness followed by:
  • Worsening of earlier symptoms
  • Petechiae
  • Ecchymosis
  • Generalized rash

• Low blood pressure
• A weak, rapid pulse
• Rash
• Red eyes
• Red throat
• Swollen glands
• Enlarged liver (hepatomegaly)

• Hematocrit
• Platelet count
• Electrolytes
• Coagulation studies
• Liver enzymes
• Blood gases
• Tourniquet test (causes petechiae below the tourniquet)
• X-ray of the chest (may demonstrate pleural effusion)
• Serologic studies (demonstrate antibodies to Dengue viruses)
• Serum studies from samples taken during acute illness and convalescence (increase in titer to Dengue antigen)