Dengue fever is a mosquito-borne viral infection that causes fever, generalized body aches, and, if severe, external and internal bleeding.

Dengue fever is common in the tropics and subtropics worldwide. It is most common in Southeast Asia but is becoming more common in Central and South America. The infection is caused by a flavivirus and is spread by mosquitoes.

Dengue fever varies in severity. Children typically have mild symptoms such as a low fever, fatigue, runny nose, and cough. Symptoms are more severe in adults and include fever, headache, and severe generalized body aches, particularly in the back, legs, and joints. These aches are often so painful that the disease has been called breakbone fever. Lymph nodes are swollen, and a rash may appear on the face. Symptoms last for 2 or 3 days, then subside. They usually recur, and a rash appears on the limbs and spreads to the trunk. The palms may be bright red, swollen, and itchy. Some people, mainly children, develop bleeding from the nose, mouth, and gastrointestinal tract (dengue hemorrhagic fever)—usually after a second infection with a dengue virus. Sometimes the blood vessels leak fluid into the lungs, causing difficulty breathing. Dengue fever is occasionally fatal.

Doctors suspect dengue fever when typical symptoms occur in people who live or have traveled in an area where the infection is common. It is usually diagnosed by blood tests for antibodies to the virus.

Treatment focuses on relieving symptoms. There is no specific treatment, but an experimental vaccine to prevent dengue fever is being tested.

Last full review/revision November 2009 by Marguerite A. Urban, MD