Alternative names
Hemorrhagic dengue; Dengue shock syndrome; Philippine hemorrhagic fever; Thai hemorrhagic fever; Dengue hemorrhagic fever

Definition
Dengue hemorrhagic fever is a severe, potentially fatal infection that occurs when someone with immunity to one type of Dengue virus is infected by a different type. It is spread by certain mosquitoes (Aedes aegypti) which bite primarily during the day. See also Dengue fever.

Causes, incidence, and risk factors

Four different dengue viruses have been implicated in both dengue fever and dengue hemorrhagic fever. Dengue hemorrhagic fever occurs when the patient contracts a different dengue virus after previous infection(s) by another type. Prior immunity to a different dengue virus type is important in the production of this severe disease.

Worldwide, more than 100 million cases of dengue fever occur every year. A small percent of these develop into dengue hemorrhagic fever. Most cases in the U.S. are brought in from other countries. It is possible for a traveler who has returned to the United States to pass the infection to someone who has not traveled.

Risk factors for dengue hemorrhagic fever include having antibodies to dengue virus from prior infection and being younger than 12, female, or Caucasian.

Symptoms

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

Acute phase symptoms include the following:

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

Signs and tests
Physical examination may reveal the following:

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

Tests may include the following:

 
• 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)

Treatment

Because Dengue hemorrhagic fever is caused by a virus for which there is no known cure or vaccine, the only treatment is to treat the symptoms.

 
• Rehydration with intravenous (IV) fluids is often necessary to treat dehydration.  
• IV fluids and electrolytes are also used to correct electrolyte imbalances.  
• A transfusion of fresh blood or platelets can correct bleeding problems.  
• Oxygen therapy may be needed to treat abnormally low blood oxygen.

Expectations (prognosis)
With early and aggressive care, most patients recover from dengue hemorrhagic fever. However, half of untreated patients who go into shock do not survive.

Complications

 
• Shock  
• Encephalopathy  
• Residual brain damage  
• Seizures  
• Liver damage

Calling your health care provider
Call your health care provider if you have symptoms of dengue fever and have been in an area where dengue fever is known to occur.

Prevention
There is no vaccine available to prevent dengue fever. Use personal protection such as full-coverage clothing, netting, mosquito repellent containing DEET, and if possible, travel during periods of minimal mosquito activity. Mosquito abatement programs can also reduce the risk of infection.

Medical Encyclopedia

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.