The disease causes severe myalgia and arthralgia earning it the names "breakbone fever"/"bone crusher disease". It presents with a petechial rash that starts on the lower limbs and chest and is characteristic of the hemorrhagic fever. The disease goes through several phases including a febrile phase, a critical phase with severe bleeding and dengue shock syndrome and a recovery phase.
After an incubation period of 2 to 7 days, the typical patient experiences the sudden onset of fever, headache, retroorbital pain, and back pain along with the severe myalgia that gave rise to the colloquial designation "break-bone fever." There is often a macular rash on the first day which is centripetal (mainly in the center of the body) and is characterized by desquamation. There may also be adenopathy, palatal vesicles, and scleral injection. The illness may last a week, with additional symptoms usually including anorexia, nausea or vomiting, marked cutaneous hypersensitivity, and -- near the time of defervescence -- a maculopapular rash beginning on the trunk and spreading to the extremities and the face. Epistaxis and scattered petechiae are often noted in uncomplicated dengue, and preexisting gastrointestinal lesions may bleed during the acute illness.
Dengue fever is diagnosed by serology, viral cultures and nucleic acid detection by PCR.
Laboratory findings include leukopenia, thrombocytopenia, and, in many cases, serum aminotransferase elevations. The diagnosis is made by IgM ELISA or paired serology during recovery or by antigen-detection ELISA or RT-PCR during the acute phase. Virus is readily isolated from blood in the acute phase if mosquito inoculation or mosquito cell culture is used.
There is no specific vaccine or treatment which in some cases requires admission to the intensive care unit. Treatment is mainly symptomatic as no specific antiviral therapy for Dengue virus exists.