Duration
The time until the outbreak of the disease (incubation period) is one to three weeks. The fever then occurring usually lasts three, maximum five days. The subsequent rash finally disappears again after about three days just as quickly as it occurred.
The three-day fever is therefore also called exanthema subitum “sudden rash”. There is no vaccination to prevent three-day fever. In order to prevent infection, one can only try to avoid contact of the child with an infected (infected) person, which is very difficult, however, since almost all people are carriers of the virus and the three-day fever can occur even without noticeable symptoms.
Since the three-day fever usually runs without complications, it is not necessary to isolate a sick child. The three-day fever is caused by human herpes viruses 6 or 7. The spread of these viruses in the population is very high.
Already in the third year of life almost all children are infected. The outbreak of the three-day fever occurs on first contact with the virus. In many cases the infection goes unnoticed without symptoms.
The virus then remains in the body for a lifetime, similar to the chickenpox virus. However, immunosuppression, i.e. suppression of the immune system by medication or various diseases such as HIV or diabetes, can lead to reactivation of the viruses and to a renewed illness. A child who has fallen ill with three-day fever usually recovers within a week. The disease is contagious, but not dangerous. Complications are very rare, and even a child who has suffered febrile convulsions due to the rapid rise in temperature during the three-day fever will not recover.
Febrile convulsions during three-day fever
In ten to fifteen percent of the cases, a three-day fever leads to febrile convulsions due to the rapid rise in fever, with rhythmic twitching of the muscles and loss of consciousness in the child. This condition is initially very frightening for the parents, but in principle the prognosis of a febrile convulsion is very good. If a febrile spasm is present, the ambulance should be called so that the child can be treated as soon as possible.
In most cases, in about 90% of the cases, this type of epileptic seizure stops on its own. If the seizure lasts longer than two minutes, medication must be administered. For example with diazepam suppositories.
You should also take antipyretic measures, such as the administration of paracetamol as a suppository. During the seizure, you should not try to hold the child to stop the seizure, because there is a risk of injury to the child. At the latest, if the febrile convulsion does not stop quickly on its own, the emergency doctor or pediatrician should be called. A febrile spasm in the course of a three-day fever is usually a so-called uncomplicated febrile spasm, so that the development of the child is not affected or at least not significantly affected.