What is “fifth disease?”

Fifth disease is a mild rash illness that occurs most commonly in children. The ill child typically has a “slapped-cheek” rash on the face and a lacy red rash on the trunk and limbs. Occasionally, the rash may itch. The rash usually spares the palms of the hands and soles of the feet. As the centers of the blotches begin to clear, the rash takes on a lacy net-like appearance. Children younger than 10 years of age are most likely to get the rash. An ill child may have a low-grade fever, headache, malaise, or a “cold” a few days before the rash breaks out. The child is usually not very ill, and the rash resolves in 7 to 10 days.

What causes fifth disease?

Fifth disease is caused by infection with human parvovirus B19. This virus infects only humans; about 50% of all adults have been infected sometime during childhood or adolescence.

Can adults get fifth disease?

Yes, they can. An adult who is not immune can be infected with parvovirus B19 and either have no symptoms or develop the typical rash of fifth disease, joint pain or swelling, or both. The joint pain and swelling usually resolve in a week or two, but they may last several months. About 50% of adults have previously been infected with parvovirus B19, have developed immunity to the virus and cannot get fifth disease.

Is fifth disease contagious?

Yes. A person infected with parvovirus B19 is contagious during the early part of the illness, before the rash appears. By the time a child has the characteristic “slapped cheek” rash of fifth disease, for example, he or she is probably no longer contagious and may return to school or child care center.

How does someone get infected with parvovirus B19?

Parvovirus B19 has been found in the respiratory secretion (e.g., saliva, sputum, or nasal mucus) of infected persons before the onset of rash, when they appear to “just have a cold.” The virus is probably spread from person to person by direct contact with those secretions, such as sharing drinking cups or utensils. In a household, as many as 50% of  susceptible persons exposed to a family member who has fifth disease may become infected. During school outbreaks, 10% to 60% of students may get fifth disease.

How soon after infection with parvovirus B19 does a person become ill?

A susceptible person usually becomes ill 4 to 14 days after being infected with the virus, but may become ill for as long as 20 days after infection.

Does everyone who is infected with parvovirus B19 become ill?

No. During outbreaks of fifth disease, about 20% of adults and children who are infected with parvovirus B19 do not develop any symptoms.

How is fifth disease diagnosed?

A physician can often diagnose fifth disease by seeing the typical rash during a physical examination. A blood test may also be done to look for antibodies to parvovirus.

How are parvovirus B19 infections treated?

Treatment of symptoms such as fever, pain, or itching is usually all that is needed for fifth disease. Adults with joint pain and swelling may need to rest, restrict their activities, and take medicines such as aspirin or ibuprofen to relieve symptoms.

Can parvovirus B19 infection be prevented?

There is no vaccine or medicine that prevents parvovirus B19 infection.

If I’m infected, what do I need to do about my pregnancy?

There is no universally recommended approach to monitor a pregnant woman who has a documented parvovirus B19 infection. Parvovirus B19 infection during pregnancy may cause problems for the unborn child. Some fetuses may develop severe anemia if the mother is infected while pregnant - especially if the infection occurs during the first half of the pregnancy. In some cases, this anemia is so severe that the fetus does not survive. Fortunately, about half of all pregnant women are immune from having had a previous infection with parvovirus. Serious problems occur in less than 5% of women who become infected during pregnancy.

Sources: CDC (Center for Disease Control and Prevention), OTIS (Organization of Teratology Information Services) and Kids Health - Nemours Foundation

Updated: December 28, 2004