by Hal B. Jenson, M.D.
Chief, Pediatric Infectious Diseases
University of Texas Health Science Center
San Antonio, TX
and
by Charles T. Leach, M.D.
Associate Professor of Pediatrics
University of Texas Health Science Center
San Antonio, TX
What is Fifth Disease?
Fifth Disease, also known as "erythema infectiosum," is a mild, self-limited viral
infection. It most commonly occurs in children, and is characterized primarily by
fever and a distinctive rash, usually over the cheeks. This distinctive rash is
responsible for another name occasionally used for this disease, "slapped-cheek
disease."
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hat causes Fifth Disease?
Fifth Disease is caused by human parvovirus B19, a DNA virus in the parvovirus family
of viruses. This is the only virus in this family that causes disease in humans.
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Parvovirus B19 predominantly infects school children. Children generally acquire
an infection during the school months, until May and June. Epidemics occur approximately
every six years, and last approximately three years.
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How does parvovirus B-19 cause disease?
Parvovirus B19 is transmitted from person-to-person by direct contact or by contaminated
secretions of the nose and the mouth. Parvovirus B19 infects the lining of the nose
and the upper respiratory tract. Then, it is spread through the blood throughout
the body, which causes the rash. The virus also infects the bone marrow cells that
are responsible for producing new red blood cells. This particular characteristic
may result in complications in those persons who have an underlying anemia or other
blood disorder.
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What are the common findings?
Fifth Disease can be divided into four phases: 1) the incubation phase, 2) the prodromal
phase, 3) the rash phase, and 4) the recovery phase. The incubation phase typically
lasts 8 to 12 days after exposure to the virus and does not have any symptoms. During
the prodromal phase, the symptoms are mild and include a headache, a low-grade fever,
fatigue, and a sore throat. These symptoms usually last for a few days and then
resolve. The rash that develops produces an intense rose-red color on both cheeks
that does not involve the area around the mouth. This rash is often referred to
as the "slapped cheek" rash because of its appearance. The rash usually lasts one
to four days and then fades. On other parts of the body, a less prominent rash can
occur at the same time or within one to two days. The chest, arms, and legs can
develop a flat red rash that has a lace-like appearance.
Adults who get a parvovirus B19 infection are more likely than children to develop
joint aches and pains. This typically develops at the time that the rash appears.
The joint symptoms usually resolve within four months, but they may persist for
a year or more.
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How is Fifth Disease diagnosed?
The infection is usually diagnosed by the characteristic appearance of the rash
in a child with a fever and no other symptoms. A blood test is available to confirm
the infection; however, it usually is not necessary.
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How is Fifth Disease treated?
Specific treatment for Fifth Disease is not available. Antibiotics are not helpful
because a virus causes Fifth Disease. Viruses cannot be treated with antibiotics.
Fever and pain should be treated with acetaminophen or ibuprofen. The disease is
usually mild with complete recovery.
Patients with underlying anemia may require a blood transfusion during the acute
illness, but they then recover to their previous state of health.
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What are the complications?
Children who have underlying anemia are at risk for developing worse anemia with
the parvovirus B19 infection. The virus infects the blood cells that produce red
blood cells and causes a temporary decrease in the production of red blood cells.
Some children require one or, occasionally, more transfusions. Usually, there is
recovery within one to two weeks, with a return to normal blood counts within three
to four weeks.
The parvovirus B19 infection in pregnant women can result in transmission of the
virus to the fetus, and the bone marrow cells of the fetus are infected. This results
in anemia in the fetus and leads to the condition known as "hydrops fetalis," which
is associated with fetal heart failure and may cause fetal death and spontaneous
abortion. However, even if a woman acquires the parvovirus B19 infection during
pregnancy, chances for fetal survival are probably 90%. The virus does not cause
birth defects or other problems if the fetus survives the period of the maternal
infection.
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How can Fifth Disease be prevented?
A vaccine is not available for the human parvovirus B19 infection. Because of the
widespread nature of the virus, there is no way to eliminate the risk of exposure.
Healthy children with Fifth Disease can attend day care or school because they are
most contagious before the rash, and are unlikely to be contagious after the onset
of the rash.
Routine exclusion of pregnant women from the workplace or social events is not recommended.
Pregnant women who find that they have been in close contact with children in the
few days before the onset of the rash of Fifth Disease, or of children who had anemia
from Fifth Disease, are at a low risk of infection and complications. Blood tests
and fetal ultrasound can help assess the possibility of infection of the fetus.
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What research is being done?
Substantial research is currently being performed to develop a vaccine to prevent
the human parvovirus B19 infection. If proved to be safe and effective, a vaccine
could be administered to children early in life to prevent infection during childhood.
The vaccine also could be administered during pregnancy to prevent the occasional
fetal death that occurs from the parvovirus B19 infection.
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About the Authors
Hal Jenson, M.D.
Dr. Jenson graduated from George Washington University School of Medicine in Washington,
DC,
He also completed a residency in pediatrics at the Rainbow Babies and Children's
Hospital of Case Western Reserve University in Cleveland, Ohio, and a fellowship
in pediatric infectious diseases and epidemiology at Yale University School of Medicine.
Dr. Jenson has an active research program on the biology of Epstein-Barr virus and
other human and non-human primate herpes viruses.
He is active in the general pediatric and infectious diseases teaching and clinical
activities of his Department and Division, is a co-editor of Nelson Textbook of
Pediatrics and of Pediatric Infectious Diseases: Principles and Practice, and authors
the book Pocket Guide to Vaccination and Prophylaxis.
Charles T. Leach, M.D.
Dr. Leach received his medical degree at the University of Utah School of Medicine
and completed his pediatrics residency as well as a fellowship in pediatric infectious
diseases at UCLA.
He is currently Associate Professor and Director of Research in the Department of
Pediatrics at the University of Texas Health Science Center at San Antonio.
Dr. Leach conducts scientific research in the areas of herpes virus infections,
pediatric AIDS, and infectious diseases among residents of the Texas-Mexico border.
Copyright 2012 Hal B. Jenson, M.D., All Rights Reserved
