HHV-6 commonly causes a febrile illness in young children between the ages of 5 to 18 months. The fevers often reach degrees Celsius. The characteristic feature of roseola is the appearance of an exanthem when the fever abates around day of illness. The erythematous rash can be macular, papular, or maculopapular; hence, the name roseola.
The rash often appears first on the face and then spreads to the trunk. There is no desquamation when the exanthem fades. Less common features of roseola include diarrhea and febrile convulsions. HHV-6 strains are divided into A and B species. Most clinical cases of roseola are caused by the B species. Although HHV-7 rarely causes symptomatic disease, on occasion, infection can resemble roseola.
The sequential appearance of high fever followed a maculopapular rash when the fever abates are the characteristic features of roseola in healthy children. Since most children acquire HHV-6 and HHV-7 infections by age 18 months, primary infection in immunocompromised children is rare. However, reactivation of these two viruses occurs commonly after immunosuppression following bone marrow and solid organ transplantation in children.
In most cases, reactivation is characterized mainly by a febrile illness with detectable viremia. In a small number of cases, especially after liver transplantation, reactivation by HHV-6 may be associated with hepatitis in the transplanted liver. HHV-6 infection also has been associated with graft rejection after liver transplantation. Any virus infection that causes a rash can lead to confusion with roseola.
These viruses include numerous enteroviruses as well as parvovirus. However, with these viral illnesses, the onset of fever and rash generally occur at the same time. Roseola can be confused with either measles or rubella in countries lacking immunization of children for the latter two diseases. Roseola is caused by HHV Most children with roseola are between 5 and 18 months of age.
The mode of transmission is still not completely understood. The most likely method is by transmission in saliva after asymptomatic reactivation in a parent or sibling. In countries such as Japan, where multigenerational families more commonly live in the same household, grandparents may be a source of infection to their grandchildren.
In the temperate Acetate de dexametasona herpes dating zone, the infection is most common during the spring months of the year. There is one additional mode of transmission, namely, intrauterine spread from a seropositive mother. HHV-6 infection is usually diagnosed by one of two methods. The second is serological testing for HHV-6 specific IgM antibody or a 4-fold rise of IgG specific antibody in two serum samples drawn at least 4 weeks apart.
For a typical case of roseola, imaging is not indicated. However, a small percentage of infants with HHV-6 will manifest seizures.
Some seizures are febrile convulsions, whereas others reflect true HHV-6 meningoencephalitis. Therefore, in infants with central nervous system complications, magnetic resonance imaging MRI may be indicated to assess the extent of viral infection in the brain.
Roseola is a virus infection that is nearly always limited by an immune response in the otherwise healthy infant. For infants with severe meningoencephalitis in the presence of a documented acute HHV-6 infection, treatment with intravenous ganciclovir should be considered. Duration of treatment has ranged from days. Since this antiviral medication is not approved for this indication in children, consultation with an infectious disease specialist should be considered before a final decision is made.
Of note, acyclovir is not efficacious against HHV-6 infection. Ganciclovir treatment can lead to serious side effects. Ganciclovir can cause bone marrow suppression and renal damage.
Therefore, the use of this antiviral medication should be restricted to the most serious HHV-6 infections, especially those involving the central nervous system of otherwise healthy children. White blood cell counts and serum creatinine levels should be monitored during the entire course of treatment. The vast majority of infants with roseola recover with no sequelae. Even those who develop febrile convulsions will usually recover completely. In the United States, permanent sequelae occur in only a small number of infants with meningoencephalitis caused by HHV-6 infection; many of these complications occur in immunocompromised children.
Of note, severe and even fatal HHV-6 encephalitis of healthy young children appears to be a more common illness in Japan. The mechanism of spread remains to be determined with certainty.
What is known is that the infection spreads mainly to infants during the second half of their first year of life, likely from asymptomatic shedding of close household contacts.
Symptomatic infections do occur in children ages two through four years. The male to female ratio is nearly equal. Most infants who contract HHV-6 infection develop too few symptoms to be diagnosed.
Therefore, the majority of young children will be seropositive by the time they reach age four years. The major complication that occurs in otherwise healthy children who contract roseola is a bout of febrile seizures.
HHV-6 infection is associated with one-third of all cases of prolonged febrile seizures in childhood. However, the prognosis is excellent in that the seizure episode does not portend an underlying seizure disorder in future years. In immunocompromised children, a reactivation occasionally leads to complications such as hepatitis and encephalitis, either of which can be severe. In a small number of children infected with HHV-6, the viral genome is integrated into a human chromosome.
Integration is particularly common after HHV-6 intrauterine infection. There is no available vaccine. A prospective study of complications and reactivation". N Engl J Med. As noted above, HHV-6 reactivation occurs commonly in children following bone marrow or organ transplantation. However, in most of these patients, reactivations of other herpesviruses, such as cytomegalovirus and Epstein-Barr virus, are also detected.
In situations where pneumonia or encephalitis develop after transplantation, HHV-6 is likely to be considered a co-pathogen and not the major pathogen. However, if after an extensive diagnostic evaluation, only HHV-6 reactivation is detected, treatment with ganciclovir can be considered.
No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. What every practitioner needs Acetate de dexametasona herpes dating know Are you sure your patient has roseola? What are the typical findings for this disease? What caused this disease to develop at this time?