Exanthema subitum

The three- day fever ( exanthema subitum, roseola infantum, Sixth disease) is an infectious disease which is caused by two different kinds of human herpes viruses. The three- day fever is one of the childhood diseases. On a three-day fever usually follows a sudden rash. Complications are rare, which is why the treatment is limited to symptomatic measures. Vaccination does not exist.

Pathogen

The three- day fever is caused by the human herpes virus 6 (HHV -6) or 7 (HHV -7). HHV -6 and HHV -7 are double-stranded DNA virus and the cytomegalovirus ( CMV, HHV -5 ) are closely related. From HHV -6 two serotypes exist ( mainly in Africa 6A and 6B primarily in Western countries ). In Europe, children will develop in practice only to type 6B. After the acute infection has subsided survived ( persisted ) the virus in the host and can be reactivated, for example, under conditions of immunosuppression.

Symptoms

The three- day fever is a disease of infancy or early infancy. By the age of three years, almost all children had contact with pathogens ( almost 100% seropositivity ). Older children and adults, therefore, practically never ill at the three- day fever. In typical course there is 3 (maximum 8) days to sustained high fever. There is evidence that a three - day fever often with a febrile seizure is accompanied as other infectious diseases. In defervescence occurs a rash with fine, sometimes slightly raised spots, which is typically located on the trunk and neck. The spots may coalesce and spread to the face.

Epidemiology

Human herpes viruses are found all over the world. Reservoir of pathogens is only for humans. Transmission occurs mainly through saliva, possibly by droplet infection. Healthy HHV- seropositive children and adults can always retire HHV in saliva. Result, these persons a continuous excitation source represents the incubation period is 5-15 days.

Complications

Among the most common complications of the HHV -6 and 7 include diarrhea and vomiting, swelling of the eyelids, papules on the soft palate and the uvula, cough, swelling of the cervical lymph nodes, bulging and tense fontanelle and febrile convulsions. The latter appear to be slightly more common in HHV -7 than in HHV- sixth

Diagnosis

In typical clinical picture with the appearance of the rash after defervescence, the diagnosis is made clinically, so there is no laboratory test is necessary. If necessary, can be found in the blood leukopenia and relative lymphocytosis. In principle, a suspected primary infection by detection of HHV- specific IgM antibodies are confirmed. Human herpes virus itself can be detected in blood, saliva and cerebrospinal fluid, HHV -7 in breast milk. These studies, however, less practical but more scientific significance. The differential diagnosis of other childhood diseases with rash such as measles, rubella, fifth disease (erythema infectiosum ) or scarlet fever is not difficult by the typical course in the rule.

Therapy

Most infections require no treatment. In case of high fever occurs, symptomatic reduction of fever. Febrile convulsions should be treated by a specific anticonvulsant medication. A virus-specific therapy does not exist.

Prophylaxis

Isolation of children with acute HHV infection is not necessary. Vaccination does not exist. Higher than the prophylactic effect of immunoglobulins previously had no knowledge.