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Dengue fever
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Dengue fever

Contributors: Casey P. Schukow DO, Vivian Wong MD, PhD, Susan Burgin MD, Paritosh Prasad MD
Other Resources UpToDate PubMed


Dengue fever, also known as breakbone fever, is caused by an RNA-containing flavivirus transmitted to humans by day-biting mosquitoes, notably Aedes aegypti, in tropical areas of the Caribbean, the Pacific Islands, Central America, South America, Southeast Asia, the Middle East, and Africa. There are estimated to be 50 million cases of dengue fever each year worldwide, and 2.5 billion people are now at risk. Travelers can present once home due to a 2- to 7-day incubation period. Clinical manifestations vary and include asymptomatic infection (75% of cases), mild dengue, classic dengue, and dengue hemorrhagic fever.

In classic dengue fever, there is a biphasic pattern to symptoms. During the first phase, there is an abrupt onset of fever for 2-5 days, malaise, chills, severe headache, myalgias, and retro-orbital and lumbosacral pain. The fever may climb as high as 41°C (105.8°F) but is not associated with an increased pulse. There can be a faint, transient diffuse morbilliform macular rash during the first few days.

During the next several days, there is defervescence despite the onset of nausea, vomiting, possible cough, rhinitis, and sore throat. Leukopenia, thrombocytopenia, and hemorrhagic manifestations are possible.

In young children with dengue fever, nonspecific symptoms such as refusing to accept oral fluids and foods, restlessness, abdominal pain, skin mottling, cold sweat, and low urine output may present early in the disease course.

Incidence is associated with increased urbanization in endemic areas. There is increased severity and 10%-30% mortality in children.

In October 2013, discovery of a new dengue virus serotype, dengue 5, was announced; it is thought to be phylogenetically distinct from the other 4 types.

Transmission of dengue virus via allogeneic blood cell transplantation has been documented, and patients with sickle cell disease or trait may be at increased risk of death from dengue.

The hemorrhagic form, dengue hemorrhagic fever (DHF), is believed to be more likely to occur during a second infection with the dengue virus, especially if the second infection involves a different serotype. DHF affects approximately 500 000 people annually and is most common in children younger than 15 years.

DHF typically begins with the abrupt onset of high fever (40°C-41°C [104°F-105.8°F]), facial flushing, circumoral cyanosis, and headache. Sore throat, anorexia, weakness, abdominal pain, nausea, and vomiting are common. This febrile phase lasts for 2-7 days and may be accompanied by a maculopapular rash, similar to dengue fever. DHF can be distinguished from dengue fever by accompanied petechiae and nonpalpable purpura present on the extremities, trunk, and face, as well as potential bleeding from the nose, gums, and gastrointestinal (GI) tract. Moderate cases will resolve after the fever subsides. However, after a few febrile days, the critical stage of plasma leakage may occur following a rapid drop in temperature. Circulatory failure accompanied by diaphoresis with cool extremities and shock may herald dengue shock syndrome (DSS). Death rates of up to 20% are reported and usually occur within 24 hours of DSS.


A90 – Dengue fever [classical dengue]

38362002 – Dengue

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Last Reviewed:11/17/2021
Last Updated:11/21/2022
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Patient Information for Dengue fever
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Contributors: Medical staff writer


Dengue fever is a viral illness passed to humans through the bite of an infected mosquito. The disease is rare in the United States, with approximately 200 cases occurring every year, but it is common worldwide, with up to 100 000 cases a year. The mosquitoes that carry the dengue fever virus (a member of the flavivirus family) live in tropical areas, and tend to bite humans during the day. There is a delay of about 2-7 days between the mosquito bite and the onset of symptoms, so it is possible that travelers to these areas will return home before they start having symptoms.

Dengue fever is not contagious between humans; it is only passed from mosquitoes to humans. However, an infected human could pass the virus back to a mosquito, which could then infect other humans. Dengue fever is also known as breakbone fever, because the illness causes terrible muscle and bone pain.

Who’s At Risk

Travelers to endemic areas, such as the Caribbean, Central America, South America, Southeast Asia, and Africa, should be aware of the risk of dengue fever. Children tend to have more severe disease with increased risk of death.

Signs & Symptoms

The symptoms of dengue fever usually occur in 2 phases, starting 2-7 days after the mosquito bite.

Early phase (first 3-4 days):
  • High fever
  • Chills
  • Eye pain
  • Headache
  • Muscle and joint pain, particularly the lower back
Later phase (second 3-4 days):
  • Diminishing fever (defervescence)
  • Rash – typically, bright red-purple dots appearing first on the arms and legs, and possibly pink-red patches all over the body
  • Nausea
  • Vomiting
  • Cough
  • Sore throat
  • Runny nose
  • Sometimes return of high fever
  • Occasionally, presence of bleeding from the nose and gums in hemorrhagic (bleeding) symptoms
  • Rarely, organ failure from massive internal bleeding

Self-Care Guidelines

To prevent dengue fever, protect yourself from all mosquito bites:
  • Wear neutral-colored long-sleeved shirts and pants that have been pretreated with a special long-lasting insecticide.
  • Cover exposed skin with insecticide.
  • Sleep under a mosquito net.
  • Avoid spending time outdoors during the day, when dengue fever mosquitoes are mostly likely to bite.
  • Get rid of areas of standing water, such as tires, flower pots, and puddles that may breed mosquitoes.
  • Before traveling to any tropical climate, check with the website to learn if there is a current dengue fever epidemic in that area.
Note: In the case of severe dengue fever, taking fever-reducing medicines such as acetaminophen, aspirin, and ibuprofen can be very harmful. Do not take these or any other medications without consulting with your doctor. For any illness with fever, be sure to rest and stay well hydrated.

When to Seek Medical Care

Always seek medical care for any illness with high fever that persists or is painful. In general, any rash that looks like red-purple pinpoint dots (petechiae), particularly if it accompanies an illness with fever, should be evaluated by a doctor.

Because dengue fever is a rare diagnosis in the United States, be sure to mention your travel history to your doctor.


Your doctor can diagnosis dengue fever by testing your blood for the presence of antibodies to the virus. There is no treatment for dengue fever. Your doctor will provide symptomatic care by treating your symptoms as they arise.

In the case of hemorrhagic (bleeding) symptoms, you may be given a blood transfusion. Usually, your doctor will prescribe fever-reducing medicines and pain medicines.

A vaccine has been approved in Brazil, Mexico, and the Philippines, and the US Food and Drug Administration (FDA) has approved a vaccine.
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Dengue fever
A medical illustration showing key findings of Dengue fever (Classic Dengue Fever, Phase 1) : Fever, Facial flushing, Headache, Arthralgia, Myalgia, Retro-orbital pain, Mosquito bite
Clinical image of Dengue fever - imageId=423445. Click to open in gallery.  caption: 'A close-up of erythematous macules and papules.'
A close-up of erythematous macules and papules.
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