After being bitten by a mosquito carrying the dengue virus, the incubation period ranges from 3 to 14 (usually 4 to 7) days before the signs and symptoms of dengue appear. Dengue occurs in two forms: Figure 1: Dengue fever symptoms. A: Hospital with dengue patients, B: Dengue fever rash, C: Patient with dengue hemorrhagic fever
Dengue hemorrhagic fever (DHF) is caused by the same viruses and is characterized by increased vascular permeability, hypovolemia, and abnormal blood clotting mechanisms. DHF is a potentially deadly complication with symptoms similar to those of dengue fever, but after several days the patient becomes irritable, restless, and sweaty. The illness often begins with a sudden rise in temperature accompanied by facial flush and other flu-like symptoms. The fever usually continues for two to seven days and
The disease manifests as a sudden onset of severe headache, chills, pain upon moving the eyes, and low backache. Painful aching in the legs and joints (myalgias and arthralgias—severe pain that gives it the nickname break-bone fever or bonecrusher disease) occurs during the first hours of illness. The temperature rises quickly as high as 40° C, with relatively low heart rate (bradycardia) and low blood pressure (hypotension). The dengue rash is characteristically bright red petechiae