Roseola is a common disease of babies or young children, in which several days of very high fever are followed by a rash. It is an extraordinarily commoninfection caused by a virus. About 90% of all children have been exposed to the virus, with about 33% actually demonstrating the syndrome of fever followed by rash. The most common age for a child to contract roseola is between sixand twelve months. Roseola infection strikes boys and girls equally. The infection may occur at any time of year, although late spring and early summer seem to be peak times for it.
About 85% of the time, roseola is caused by a virus called Human Herpesvirus6, or HHV-6. Although the virus is related to those herpesviruses known to cause sores on the lips or genitalia, HHV-6 causes a very different type of infection. HHV-6 is believed to be passed between people via infected saliva. Afew other viruses (called enteroviruses) can produce a similar fever-then-rash illness, which is usually also called roseola.
Researchers believe that it takes about 5-15 days to develop illness after having been infected by HHV-6. Roseola strikes suddenly, when a previously-wellchild spikes an impressively high fever. The temperature may reach 106°F. As is always the case with sudden fever spikes, the extreme change in temperature may cause certain children to have seizures. About 5-35% of all children with roseola will have these "febrile seizures."
The most notable thing about this early phase of roseola is the absence of symptoms, other than the high fever. Although some children have a slightly reddened throat, or a slightly runny nose, most children have no symptoms whatsoever, other than the sudden development of high fever. This fever lasts for between three and five days.
Somewhere around the fifth day, a rash begins on the body. The rash is usually composed of flat pink patches or spots, although there may be some raised patches as well. The rash usually starts on the chest, back, and abdomen, andthen spreads out to the arms and neck. It may or may not reach the legs and face. The rash lasts for about three days, then fades.
Very rarely, roseola will cause more serious disease. Patients so afflicted will experience significant swelling of the lymph nodes, the liver, and the spleen. The liver may become sufficiently inflamed to interfere with its functioning, resulting in a yellowish color to the whites of the eyes and the skin(jaundice). This syndrome (called a mononucleosis-like syndrome, after the disease called infectious mononucleosis that causes many of the same symptoms)has occurred in both infants and adults.
The diagnosis of roseola is often made by carefully examining the feverish child to make sure that other illnesses are not causing the temperature spike.Once it is clear that no pneumonia, ear infection, strep throat, or other common childhood illness is present, the practitioner usually feels comfortablewaiting to see if the characteristic rash of roseola begins.
There are no treatments available to stop the course of roseola. Acetaminophen or ibuprofen is usually given to try to lower the fever. Children who are susceptible to seizures may be given a sedative medication when the fever first spikes, in an attempt to prevent such a seizure. Children recover quickly and completely from roseola. The only complications are those associated withseizures, or the rare mononucleosis-like syndrome.
Other than the usual good hygiene practices always recommended to decrease the spread of viral illness, no methods are available to specifically prevent roseola.