Overview

Roseola is a generally mild infection that usually affects children by age 2. It occasionally affects adults. Roseola is so common that most children have been infected with roseola by the time they enter kindergarten.

Two common strains of herpes virus cause roseola. The condition typically causes several days of fever, followed by a rash.

Some children develop only a very mild case of roseola and never show any clear indication of illness, while others experience the full range of signs and symptoms.

Roseola typically isn't serious. Rarely, a very high fever can result in complications. Treatment of roseola includes bed rest, fluids and medications to reduce fever.

Symptoms

If your child is exposed to someone with roseola and becomes infected with the virus, it generally takes a week or two for signs and symptoms of infection to appear — if they appear at all. It's possible to become infected with roseola, but have signs and symptoms too mild to be readily noticeable. Roseola symptoms may include:

  • Fever. Roseola typically starts with a sudden, high fever — often greater than 103 F (39.4 C). Some children may also have a slightly sore throat, runny nose or cough along with or preceding the fever. Your child may also develop swollen lymph nodes in his or her neck along with the fever. The fever lasts three to five days.
  • Rash. Once the fever subsides, a rash typically appears — but not always. The rash consists of many small pink spots or patches. These spots are generally flat, but some may be raised. There may be a white ring around some of the spots. The rash usually starts on the chest, back and abdomen and then spreads to the neck and arms. It may or may not reach the legs and face. The rash, which isn't itchy or uncomfortable, can last from several hours to several days before fading.

Other signs and symptoms of roseola may include:

  • Irritability in infants and children
  • Mild diarrhea
  • Decreased appetite
  • Swollen eyelids

When to see a doctor

Seek immediate medical care

Your child could have a convulsion (febrile seizure) if his or her fever becomes high or spikes quickly. However, usually by the time you notice your child's high temperature, the threat of a possible seizure has already passed. If your child does have an unexplained seizure, seek medical care immediately.

Call your child's doctor

Call your child's doctor if:

  • Your child has a fever greater than 103 F (39.4 C)
  • Your child has roseola and the fever lasts more than seven days
  • The rash doesn't improve after three days

Call your doctor

If your immune system is compromised and you come in contact with someone who has roseola, contact your doctor. You may need monitoring for a possible infection that, for you, could be more severe than it is for a child.

Causes

The most common cause of roseola is the human herpes virus 6, but the cause also can be another herpes virus — human herpes virus 7.

Like other viral illnesses, such as a common cold, roseola spreads from person to person through contact with an infected person's respiratory secretions or saliva. For example, a healthy child who shares a cup with a child who has roseola could contract the virus.

Roseola is contagious even if no rash is present. That means the condition can spread while an infected child has only a fever, even before it's clear that the child has roseola. Watch for signs of roseola if your child has interacted with another child who has the illness.

Unlike chickenpox and other childhood viral illnesses that spread rapidly, roseola rarely results in a communitywide outbreak. The infection can occur at any time of the year.

Risk factors

Older infants are at greatest risk of acquiring roseola because they haven't had time yet to develop their own antibodies against many viruses. While in the uterus, babies receive antibodies from their mothers that protect them as newborns from contracting infections, such as roseola. But this immunity decreases with time. The most common age for a child to contract roseola is between 6 and 15 months.

Complications

Seizures in children

Occasionally a child with roseola experiences a seizure brought on by a rapid rise in body temperature. If this happens, your child might briefly lose consciousness and jerk his or her arms, legs or head for several seconds to minutes. He or she may also lose bladder or bowel control temporarily.

If your child has a seizure, seek emergency care. Although frightening, fever-related seizures in otherwise healthy young children are generally short-lived and are rarely harmful.

Complications from roseola are rare. The vast majority of otherwise healthy children and adults with roseola recover quickly and completely.

Concerns for people with weak immune systems

Roseola is of greater concern in people whose immune systems are compromised, such as those who have recently received a bone marrow or organ transplant. They may contract a new case of roseola — or a previous infection may come back while their immune system is weakened. Because they have less resistance to viruses in general, immune-compromised people tend to develop more-severe cases of infection and have a harder time fighting off illness.

People with weak immune systems who contract roseola may experience potentially serious complications from the infection, such as pneumonia or encephalitis — a potentially life-threatening inflammation of the brain.

Prevention

Because there's no vaccine to prevent roseola, the best you can do to prevent the spread of roseola is to avoid exposing your child to an infected child. If your child is sick with roseola, keep him or her home and away from other children until the fever has broken.

Most people have antibodies to roseola by the time they're of school age, making them immune to a second infection. Even so, if one household member contracts the virus, make sure that all family members wash their hands frequently to prevent spread of the virus to anyone who isn't immune.

Adults who never contracted roseola as children can become infected later in life, though the disease tends to be mild in healthy adults. However, infected adults can pass the virus on to children.

May 28, 2015
References
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  3. Mamishi S, et al. Prevalence of HHV-6 in cerebrospinal fluid of children younger than 2 years of age with febrile convulsion. Iranian Journal of Microbiology. 2014;6(2):87. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4281666/. Accessed April 8, 2015.
  4. Roseola infantum. The Merck Manual Professional Edition. http://www.merckmanuals.com/professional/pediatrics/miscellaneous_viral_infections_in_infants_and_children/roseola_infantum.html?qt=human herpesvirus 6&alt=sh. Accessed April 8, 2015.
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  6. What is the role of aspirin in triggering Reye's? National Reye's Syndrome Foundation. http://www.reyessyndrome.org/aspirin.html. Accessed April 8, 2015.