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Fifth
Disease
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. An ill child may have a low-grade fever, 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. Pet dogs or cats may be immunized against "parvovirus,"
but these are animal parvoviruses that do not infect humans. Therefore,
a child cannot "catch" parvovirus from a pet dog or cat, and
a pet cat or dog cannot catch human parvovirus B19 from an ill child.
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. Usually, joints on both sides of the
body are affected. The joints most frequently affected are the hands,
wrists, and knees. The joint pain and swelling usually resolve in a week
or two, but they may last several months. About 50% of adults, however,
have been previously 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. This contagious period is different than
that for many other rash illnesses, such as measles, for which the child
is contagious while he or she has the rash.
How does someone get infected with parvovirus B19?
Parvovirus B19 has been found in the respiratory secretions (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. Furthermore,
other persons infected with the virus will have a non-specific illness
that is not characteristic of fifth disease. Persons infected with the
virus, however, do develop lasting immunity that protects them against
infection in the future.
How is fifth disease diagnosed?
A physician can often diagnose fifth disease by seeing the typical rash
during a physical examination. In cases in which it is important to confirm
the diagnosis, a blood test may be done to look for antibodies to parvovirus.
Antibodies are proteins produced by the immune system in response to parvovirus
B19 and other germs. If immunoglobulin M (IgM) antibody to parvovirus
B19 is detected, the test result suggests that the person has had a recent
infection.
Is fifth disease serious?
Fifth disease is usually a mild illness that resolves on its own among
children and adults who are otherwise healthy. Joint pain and swelling
in adults usually resolve without long-term disability.
Parvovirus B19 infection may cause a serious illness in persons with
sickle-cell disease or similar types of chronic anemia. In such persons,
parvovirus B19 can cause an acute, severe anemia. The ill person may be
pale, weak, and tired, and should see his or her physician for treatment.
(The typical rash of fifth disease is rarely seen in these persons.) Once
the infection is controlled, the anemia resolves. Furthermore, persons
who have problems with their immune systems may also develop a chronic
anemia with parvovirus B19 infection that requires medical treatment.
People who have leukemia or cancer, who are born with immune deficiencies,
who have received an organ transplant, or who have human immunodeficiency
virus (HIV) infection are at risk for serious illness due to parvovirus
B19 infection.
Occasionally, serious complications may develop from parvovirus B19 infection
during pregnancy. For details, please see the CDC information sheet entitled,
"Parvovirus B19 Infection and Pregnancy."
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. The few people who have severe
anemia caused by parvovirus B19 infection may need to be hospitalized
and receive blood transfusions. Persons with immune problems may need
special medical care, including treatment with immune globulin (antibodies),
to help their bodies get rid of the infection.
Can parvovirus B19 infection be prevented?
There is no vaccine or medicine that prevents parvovirus B19 infection.
Frequent handwashing is recommended as a practical and probably effective
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This page
last reviewed September 7, 2000
Centers for Disease Control and Prevention
National Center for Infectious Diseases
Division of Viral and Rickettsial Diseases
Respiratory and Enteric Viruses Branch
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