Roseola

Picture of a roseola rash. SOURCE: Image Source: Getty Images

• Roseola is a mild viral illness most commonly in young children.
• Roseola is a common viral infection.
• Roseola is also termed the sixth disease, roseola infantum, and exanthema subitum.
• A sudden high fever that lasts for three to five days is an early feature of roseola. Mild nasal congestion and loose stools may accompany the fever.
• When the fever disappears, a rash appears, which may last one to two days.
• The rash of roseola is not contagious.
• Roseola usually resolves without any treatment.

• Roseola is a mildly contagious illness caused by either one of two viruses. Characteristically, roseola has a sudden onset and relatively short duration.
• Roseola is most common in children 6-24 months of age, with an average age of 9 months. Less frequently, older children, teens, and (rarely) adults may be infected.

Roseola is referred to by several other names. It was formally called roseola infantum or roseola infantilis. Because the rash appears so suddenly (right after the fever dramatically departs), the disease is commonly called exanthem subitum.

To distinguish roseola from other childhood diseases featuring skin rashes, it was once dubbed "sixth disease" (because it was the sixth disease young children typically developed, and it lasted about 6 days). But that name has largely been forgotten.

Roseola is primarily caused by a virus called human herpesvirus 6 (HHV-6) and less frequently by human herpesvirus 7 (HHV-7).

The signs and symptoms of HHV-6 (or HHV-7) infection vary depending on the age of the patient.

• Infants and toddlers routinely develop sudden symptoms with an abrupt onset of a high fever (103-104 degrees) that lasts for 3-5 days.
• The child may also develop irritability, swollen glands in the front or back of the neck, runny nose, puffy eyelids, and mild diarrhea.
• Within 12-24 hours of the fever breaking, a rash rapidly appears.
• Older children who develop HHV-6 (or HHV-7) infection are more likely to have an illness characterized by several days of high fever and possibly a runny nose and/or diarrhea.
• Older children less commonly develop a rash as the fever abates.

Many studies have shown that the large majority of those infected with the HHV-6 or HHV-7 virus have no obvious symptoms. Their immune system clears the virus before the development of any symptoms. For those individuals who do develop an overt infection, the vast majority sustain no side effects. A rare individual with a compromised immune system may be at risk for a more complicated course of the disease. This would include newborn infants (first six to eight weeks of life), individuals receiving chemotherapy, or those with an illness that impacts the immune system (such as HIV-AIDS).

Roseola is spread from person to person, typically by transfer of oral secretions.

• The incubation period between exposure to the virus and onset of symptoms is nine to 10 days.
• Humans are the only natural hosts for HHV-6 and HHV-7.
• Unlike some other viral infections, roseola occurs throughout the year without seasonal variation.

Pediatricians and family practitioners are capable of diagnosing and managing a child with roseola. Specialists (infectious disease experts) are rarely needed to assist in the care of this generally benign disease.

The characteristic clinical pattern of sudden onset of high fever and development of the typical rash at the time of fever resolution generally enables a rapid diagnosis without any laboratory studies. For unusual presentations, patients with complications, or those with immune deficiency states, several forms of blood tests can assist in establishing the diagnosis.

If the fever is not causing the child to be uncomfortable, the fever need not be treated. It is not necessary to awaken the child to treat a fever unless instructed to do so by a healthcare professional.

If someone wants to treat the fever, acetaminophen (Tylenol and others) can be used. The dosage interval is every 4 hours. Ibuprofen (Advil, Motrin, and others) may be used instead of acetaminophen on an every 6-hour basis. Both families of medication are equally effective in lowering a child's fever. There is no medical benefit in alternating acetaminophen with ibuprofen. Aspirin should never be used for fever in children or adolescents.

A child with a fever should be kept comfortable and not be overdressed. Overdressing can cause the temperature to go higher. Bathing with tepid water (85 F or 29.5 C) may help bring down a fever by 1 to 1.5 degrees. If a child develops shivering during the bath, the temperature of the bath water should be raised. Never sponge a child (or an adult) with alcohol; the alcohol fumes may be inhaled, causing many problems.

Since roseola patients experience a moderate fever, medications to lower fever (antipyretics) help lower fever and lessen any associated discomfort (such as headache). Such medications include acetaminophen and/or ibuprofen. A cool bath (approximate water temperature of 85 degrees) may also be therapeutic. No therapy is necessary regarding the rash of roseola since it does not cause symptoms, it is short-lived, and it resolves spontaneously.

The hardest thing to do is to keep calm while helping the child to the floor and loosening any clothing around the neck. Remove any sharp objects that could cause injury, and turn the child on one side so saliva can flow from the mouth. Putting a cushion or a folded coat under the head for a pillow is fine, but do not put anything in the child's mouth. The best thing is just to wait it out.

Most febrile seizures (whether associated with roseola or other viruses) last less than 5 minutes. Do not leave the child unattended while calling the paramedics to the doctor's office. Children are often drowsy and sleep after a seizure. That is normal. After the seizure, contact the child's healthcare professional to determine if the child should be immediately examined.

Yes. The sudden and rapid rise in temperature elevation may trigger a seizure (a convulsion). Febrile seizures (convulsions due to fever) are common (3%) in children between 18 months to 3 years of age. They occur in 5%-35% of children with roseola.

The seizure may look very frightening, but it is usually quite harmless (benign). Febrile seizures are not associated with long-term nervous-system side effects or brain damage. Anticonvulsant medications are very rarely prescribed for the treatment or prevention of febrile seizures.

The fever can be quite high. The fever averages 103.5 F (39.7 C), but it can go up as high as 106 F (41.2 C).

Yes, but not in the beginning. When the fever disappears, a rash appears. The rash is mainly located on the neck and torso (the abdomen, trunk, and back), but it can also be on the arms and legs (extremities).

The rash may appear as separate little raised ("goose bump" size) dots (papules) or as a flat (macular) rash. The skin is often mildly red and temporarily blanches with pressure. The rash is not itchy or painful. It is not contagious. The rash lasts one to two days and does not return.

What is most striking is that the child seems so well despite having a high fever.

The fever of roseola lasts 3-5 days followed by a rash lasting about one to two days that resolves without treatment. Immunity to HHV-6 seems to be lifelong.

Complications are rare with roseola except in children with suppressed immune systems. Individuals with healthy immune systems generally develop lifelong immunity to HHV-6 (or HHV-7).

Yes, an evaluation by a healthcare professional is a good idea. A child with a fever and a rash should not go back to childcare until they are medically evaluated.

A child with just the rash of roseola and no fever for 24 hours can usually return to childcare.

At this time, there is no vaccine for roseola. Due to its generally benign nature and rare rate of complications, many researchers doubt that the high financial cost to develop such a new vaccine would be worthwhile.

The primary mechanism for HHV-6 or HHV-7 transmission is via human-to-human respiratory droplet secretions. Therefore, basic hand-washing and avoidance of acutely ill individuals (such as those with fever) is the best way to avoid contracting the illness. Daycare centers and preschools should follow routine principles of hygiene and decontamination of toys and articles shared by their children.

Except for immune-compromised patients, the prognosis for a child with roseola is excellent and no long-term side effects should occur.