Conditions Basics

What is roseola?

Roseola (roseola infantum) is a mild illness caused by a virus. It is generally harmless and is most common in children 6 months to 2 years of age. It is rare after age 4.

What causes it?

Roseola is caused by two common viruses. The viruses belong to the family of herpes viruses, but they do not cause the cold sores or genital infections that herpes simplex viruses can cause. They are spread through tiny droplets of fluid from the nose and throat of infected people when they laugh, talk, sneeze, or cough. Roseola mostly spreads from infected people who don't show symptoms.

If your child has roseola, keep him or her at home until there has been no fever for 24 hours and he or she is feeling better.

What are the symptoms?

Roseola often starts with a sudden high fever 39.4°C (103°F) to 40.6°C (105°F) that lasts 2 to 3 days, although it can last up to 8 days. The rapid increase in temperature may be the first sign of roseola and often occurs before you realize that your child has a fever. The fever ends suddenly.

After the fever ends, a rosy-pink rash may appear mostly on the trunk (torso), neck, and arms. The rash is not itchy and may last 1 to 2 days.

In rare cases, a sore throat, stomach ache, vomiting, and diarrhea occur.

A child with roseola may appear fussy or irritable and may have a decreased appetite, but most children behave almost normally.

Roseola generally is a harmless viral infection. Like any illness that can cause a fever, it can cause fever seizures, which are uncontrolled muscle spasms and unresponsiveness that last 1 to 3 minutes. The fever seizure is caused by the rapid increase in temperature in a short period of time. After a fever has reached a high temperature, the risk of a seizure is probably over.

How is it diagnosed?

Roseola is diagnosed through a medical history and physical examination. The doctor often knows it's roseola if your child had a fever and now has a distinct rash.

How is roseola treated?

The roseola fever can be managed with acetaminophen (such as Tylenol) or ibuprofen (such as Advil or Motrin). Be safe with medicines. Read and follow all instructions on the label. If you give medicine to your baby, follow your doctor's advice about what amount to give. Do not give aspirin to anyone younger than 18 years of age because of the risk of Reye syndrome.

The roseola rash will go away without medical treatment.