Synonyms in a broader sense
Medical: Exanthema subitum, Roseola infantum, Sixth disease
Definition
Three-day fever is a common infectious disease caused by viruses and mainly affects infants and toddlers. It is usually a harmless childhood disease that heals without consequences and leaves behind a lifelong immunity. Typically, a high fever lasting several days is followed by a small spotted rash in the case of three-day fever (exanthema), which appears as soon as the fever drops (rash after fever).
How dangerous is that?
The three-day fever takes a two-phase course, with the first phase being dominated by high fever. In connection with the fever, due to the typical age of the patients, febrile convulsions may occur between 6 months and 6 years of age. These often frighten and frighten the affected parents at the first attack, but they are usually harmless and end after a few minutes without any residual impairment of the child.
Three days after the beginning of the fever, the second phase follows, which is determined by the typical skin appearance. After three days at the latest, these fade again. Only in very rare cases does a severe inflammatory course occur with the transition to meningoencephalitis (inflammation of the meninges and brain tissue).
Forms of the three-day fever
In most cases the disease takes its typical course with high fever and subsequent rash. However, it can also happen that a child has high fever for several days, which is caused by an infection with the pathogen that causes three-day fever (HHV-6), without subsequently developing a rash (“abortive form”). In 20% of the cases, the disease does not develop at all (asymptomatic form), the disease proceeds “silently” without being noticed. In older children, the three-day fever can be similar to mononucleosis (Epstein-Barr-Virus, Pfeiffer’s glandular fever) with characteristics of an inflammation of the liver in the blood.
EpidemiologyPopulation incidence
The three-day fever mainly affects children between 6 months and 3 years of age. By the age of 3 years, almost all children have had contact with the pathogen. The viruses that cause the disease (HHV-6, HHV-7) are spread worldwide and are only passed on from person to person.
Infection with the three-day fever occurs via droplet infection, mostly through: the sick child, which is inhaled by other children or absorbed through the hands. The child is contagious a few days before the appearance of the disease characteristics (symptoms), and usually no longer after the appearance of the rash.
- Cough,
- Sneeze or
- Saliva
The pathogens causing the three-day fever are the viruses Human Herpes Virus 6 (HHV-6) or, more rarely, Human Herpes Virus 7 (HHV-7).
Although they belong to the same family as the better known Herpes Simplex Virus (HSV), they do not cause the commonly known cold sore or genital herpes. When a child is infected with the three-day fever via droplet infection, the pathogen cells in the salivary glands multiply in the body and after a few days (incubation period) the viruses enter the bloodstream, spread in the body and thus the appearance of the disease characteristics (symptoms). Like all herpes viruses, HHV-6 and HHV-7 can remain in the body for life (persistence) and become active again (reactivation) if the immune system is weakened (e.g. immunosuppression). This leads to a recurrence of symptoms without being infected again. Repeated infection with the three-day fever as an adult may occur, but it is not common, as it is assumed that the illness experienced in childhood results in lifelong protection (immunity).