dengue fever

Overview
Dengue fever is a mosquito-borne viral infection caused by the dengue virus (DENV), which has four different strains (DENV-1 through DENV-4). It causes a sudden onset of fever, severe muscle and joint pain, headaches, and rash. It's commonly referred to as "breakbone fever" because of the intense body aches it can cause.

Why It’s Important
Dengue affects millions globally each year and can become severe, especially during second infections with a different strain. Severe dengue (also known as dengue hemorrhagic fever) can lead to bleeding, organ failure, and death, especially without prompt care.

Quick Facts

  • Transmitted by Aedes mosquitoes (especially Aedes aegypti)

  • Most common in tropical and subtropical regions (South Asia, Latin America, Caribbean, Pacific Islands)

  • Affects all age groups but tends to be more severe in children and the elderly

  • Estimated 400 million infections occur globally each year (WHO)

  • Can be mild to life-threatening, and infection with one strain doesn’t protect against the others

What Happens in the Body
After a bite from an infected mosquito, the virus enters the bloodstream and begins to replicate in white blood cells. The immune system responds with inflammation, causing fever and body aches. In some cases, especially with repeated infections, the immune response becomes overly aggressive, leading to leaky blood vessels, low platelets, and bleeding complications.

Common Signs and Symptoms
Symptoms usually appear 4–10 days after the bite and can last up to a week:

  • High fever (up to 104°F or 40°C)

  • Severe headaches

  • Pain behind the eyes

  • Muscle, bone, and joint pain

  • Nausea and vomiting

  • Skin rash (usually appears 2–5 days after the fever starts)

  • Mild bleeding (nosebleeds, gum bleeding, easy bruising)

Signs of Severe Dengue (requires urgent care):

  • Severe abdominal pain

  • Persistent vomiting

  • Bleeding from the nose or gums

  • Blood in vomit or stool

  • Rapid breathing

  • Fatigue or restlessness

Diagnosis

  • Blood tests to detect the virus or antibodies (e.g., NS1 antigen test, IgM/IgG antibodies)

  • Complete blood count (CBC) to monitor platelets and white blood cells

  • Medical attention should be sought if high fever is accompanied by bleeding, severe pain, or travel history to dengue-endemic regions

Treatment and Management

  • No specific antiviral treatment; supportive care is key

  • Fluids and rest are crucial to prevent dehydration

  • Acetaminophen (paracetamol) for fever and pain

  • Avoid NSAIDs like ibuprofen or aspirin—they increase bleeding risk

  • Hospitalization may be required for severe cases, especially to manage fluid balance and bleeding

Risks and Complications

  • Severe dengue (dengue hemorrhagic fever)

  • Dengue shock syndrome (DSS), which can cause dangerously low blood pressure

  • Low platelet count, leading to internal bleeding

  • Organ damage or failure in critical cases

  • Death, especially in vulnerable populations or where access to healthcare is limited

Who Is at Risk

  • People living in or traveling to dengue-endemic areas

  • Individuals with a previous dengue infection (higher risk of severe dengue)

  • Infants and children

  • Elderly adults and those with chronic illnesses

  • Areas with poor mosquito control

Related Conditions

  • Zika virus (transmitted by the same mosquito and can present similarly)

  • Chikungunya virus

  • Malaria and typhoid fever (can mimic dengue symptoms and must be ruled out)

  • Leptospirosis, COVID-19, and other febrile illnesses in endemic regions

When to See a Doctor

  • If you develop high fever and any dengue symptoms after traveling to or living in a dengue-prone area

  • If you notice bleeding, severe stomach pain, or vomiting blood

  • If symptoms worsen after the fever drops—this is a critical warning sign for severe dengue

  • Always consult a healthcare provider before taking pain relievers or fever reducers

Last Updated: June 21, 2025