Roseola

Definition
Roseola is a contagious childhood disease characterized by a high fever followed by a rash. Roseola is also known as exanthem subitum, pseudorubella, roseola infantum and sixth disease.

Causes/associated factors
Roseola is caused by human herpes virus-6 (HHV-6) and less commonly by human herpes virus-7 (HHV-7). The infection primarily affects children ages 6 months to 3 years. Younger children rarely develop the infection -- they're most likely protected by antibodies received from their mothers at birth. By age 2, however, 65 to 100 percent of children have been infected with the virus. It can strike at any time during the year. Once a child has the infection, permanent immunity often develops. In otherwise healthy children, roseola is rarely serious and typically has no lasting complications.

Transmission
The virus has been found in saliva, lymph nodes, and cells of the kidney, liver and blood, but the route of transmission is unclear. After an acute infection of roseola, the virus can remain inactive in these areas of the body and be a potential source of infection to a susceptible person. It's thought that a child may contract roseola through exposure to caregivers, parents or other children who have the virus in their saliva. Although uncommon, minor community outbreaks have been reported. Roseola has also developed after liver and kidney transplants in people who haven't had the infection.
The incubation period (time from exposure until symptoms appear) is five to 15 days.


Signs/symptoms
In some cases, roseola has no symptoms. When symptoms appear, the main symptom of roseola is a sudden high fever without an apparent cause. The fever may be up to 103 to 105°F and last three to five days. The child may look well or only mildly ill despite the presence of the fever. Five to 10 percent of children who have roseola have a seizure while the fever is present.
Another classic symptom is a rosy-colored rash that, if present, appears on the trunk, buttocks and neck when the fever fades. It may also show up mildly on your child's face, arms and legs. The rash is generally flat or slightly elevated, and the small pink spots may turn white under pressure. The rash doesn't usually itch. It can last just a few hours or up to three days.

Other possible symptoms of roseola include:

irritability
appetite loss
mild diarrhea or vomiting
cough or runny nose
red throat
inflamed eardrums
swollen lymph nodes in the head and neck
swollen eyelids
bulging anterior fontanel (soft spot in the skull)

Diagnosis
The doctor will ask about your child's symptoms and do a physical exam. Because the rash is sometimes confused with measles or rubella, special blood tests may be needed. If the child was put on an antibiotic medication for the high fever, the rash may sometimes be mistaken for a drug allergy.

Treatment
If a rash is present, it typically resolves on its own within several hours to a few days. If your child has a fever, the doctor may suggest the following steps:
Use acetaminophen or ibuprofen, according to your doctor's instructions. (Ibuprofen medications, such as Advil or Motrin, are recommended for children 6 months and older.) Do not give aspirin to anyone under age 19 -- it may increase the risk of Reye's syndrome, a rare but serious illness involving the brain and liver following a viral infection.

Cool your child with warm sponge baths. Cold water could cause shivering, sending your child's temperature back up.

Dress your child in lightweight clothing.

Keep the room temperature normal.

Encourage your child to rest.

Offer your child plenty of fluids to replace those lost due to the fever.
If a person is severely ill or has a weak immune system, antiviral medication may be prescribed.


Complications
Some children have seizures due to the fever (known as febrile seizures). Rarely, meningitis (inflammation of the membranes surrounding the brain or spinal cord) or encephalitis (inflammation of the brain) may develop.
For adults, the infection may produce a severe mononucleosis-like infection. It has also been know to cause hepatitis (inflammation of the liver).

HHV-6 virus can survive in the body and reactivate in adults with weak immune systems, such as transplant patients or those infected with HIV (the virus that causes AIDS). These reactivated infections may cause encephalitis (inflammation of the brain) or pneumonitis (inflammation of the lungs). They are often severe and can sometimes be fatal.


Pregnancy-specific information
Roseola contracted during pregnancy appears to have no harmful effect for mother or baby.

Senior-specific information
Growing older is not a risk factor for roseola.

Prevention
There are no specific recommendations for prevention because it's not clearly understood how roseola spreads. However, it's best to keep children who have a fever due to roseola away from others who have not yet had the disease.