infectious diseases
Dengue
Symptoms and Signs of Dengue
After an incubation period of 3 to 15 days, fever, chills, headache, retro-orbital pain with eye movement, lumbar backache, and severe prostration begin abruptly. Extreme aching in the legs and joints occurs during the first hours, accounting for the traditional name of breakbone fever. The temperature rises rapidly to up to 40°C, with relative bradycardia. Bulbar and palpebral conjunctival injection and a transient flushing or pale pink macular rash (particularly of the face) may occur. Cervical, epitrochlear, and inguinal lymph nodes are often enlarged. Fever and other symptoms persist 48 to 96 hours, followed by rapid defervescence with profuse sweating. Patients then feel well for about 24 hours, after which fever may occur again (saddleback pattern), typically with a lower peak temperature than the first. Simultaneously, a blanching maculopapular rash spreads from the trunk to the extremities and face. Sore throat, gastrointestinal symptoms (eg, nausea, vomiting), and hemorrhagic symptoms can occur. Some patients develop Dengue Hemorrhagic Fever/Dengue Shock Syndrome . Neurologic symptoms are uncommon and can include encephalopathy and seizures; some patients develop Guillain-Barré Syndrome (GBS) . Mild cases of dengue, usually lacking lymphadenopathy, remit in<72 hours. In more severe disease, asthenia may last several weeks. Death is rare. Immunity to the infecting strain is long-lasting, whereas broader immunity to other strains lasts only 2 to 12 months. More severe disease may result from antibody-dependent enhancement of infection, in which patients have a non-neutralizing antibody from a previous infection with one dengue serotype and then have another infection with a different dengue serotype. 