What's Fifth Disease?
Especially common in kids between the ages of 5 and 15, fifth
disease typically produces a distinctive red rash on the face that
makes the child appear to have a "slapped cheek." The
rash then spreads to the trunk, arms, and legs. Fifth disease is
actually just a viral illness that most kids recover from quickly
and without complications.
Fifth disease (also called erythema infectiosum) is caused by
parvovirus B19. A human virus, parvovirus B19 is
not
the same parvovirus that veterinarians may be concerned about in
pets, especially dogs, and it
cannot
be passed from humans to animals or vice versa.
Studies show that although 40% to 60% of adults worldwide have
laboratory evidence of a past parvovirus B19 infection, most of
these adults can't remember having had symptoms of fifth
disease. This leads medical experts to believe that most people
with a B19 infection have either very mild symptoms or no symptoms
at all.
Fifth disease occurs everywhere in the world. Outbreaks of
parvovirus tend to happen in the late winter and early spring, but
there may also be sporadic cases of the disease any time throughout
the year.
Signs and Symptoms
Fifth disease begins with a low-grade
fever
, headache, and mild cold-like symptoms (a stuffy or runny nose).
These symptoms pass, and the illness seems to be gone until a rash
appears a few days later. The bright red rash typically begins on
the face. Several days later, the rash spreads and red blotches
(usually lighter in color) extend down to the trunk, arms, and
legs. 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. Kids younger than 10 years old
are most likely to get the rash.
Older kids and adults sometimes complain that the rash itches,
but most children with a rash caused by fifth disease do not look
sick and no longer have fever. It may take 1 to 3 weeks for the
rash to completely clear, and during that time it may seem to
worsen until it finally fades away entirely.
Certain stimuli (including sunlight, heat, exercise, and stress)
may reactivate the rash until it completely fades. Other symptoms
that sometimes occur with fifth disease include swollen glands, red
eyes, sore throat, diarrhea, and rarely, rashes that look like
blisters or bruises.
In some cases, especially in adults and older teens, an attack
of fifth disease may be followed by joint swelling or pain, often
in the hands, wrists, knees, or ankles.
Contagiousness
A person with parvovirus infection is most contagious before the
rash appears - either during the incubation period (the time
between infection and the onset of symptoms) or during the time
when he or she has only mild respiratory symptoms. Because the rash
of fifth disease is due to an immune reaction (a defense response
launched by the body against foreign substances like viruses) that
occurs after the infection has passed, a child is usually not
contagious once the rash appears.
Parvovirus B19 spreads easily from person to person in fluids
from the nose, mouth, and throat of someone with the infection,
especially through large droplets from coughs and sneezes.
In households where a child has fifth disease, another family
member who hasn't previously had parvovirus B19 has about a 50%
chance of also getting the infection. Children with fifth disease
may attend childcare or school, since they are no longer
contagious. Once infected with parvovirus B19, a
person develops immunity to it and won't usually become
infected again.
Parvovirus B19 infection during pregnancy may cause problems for
the fetus. 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 doesn't 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.
Prevention
There is no vaccine for fifth disease, and no real way to
prevent spreading the virus. Isolating someone with a fifth disease
rash won't prevent spread of the infection because the person
usually isn't contagious by that time.
Practicing good hygiene, especially frequent
hand washing
, is always a good idea since it can help prevent the spread of
many infections.
Incubation
The incubation period (the time between infection and the onset
of symptoms) for fifth disease ranges from 4 to 28 days, with the
average being 16 to 17 days.
Duration
The rash of fifth disease usually lasts 1 to 3 weeks. In a few
cases in older kids and adults, joint swelling and pain because of
fifth disease have lasted from a few months up to a few years.
Diagnosis
Doctors can usually diagnose fifth disease by the distinctive
rash on the face and body. If a child or adult has no telltale rash
but has been sick for a while, a doctor may perform blood tests to
see if the illness could be caused by parvovirus B19.
Treatment
Fifth disease is caused by a virus, and it cannot be treated
with
antibiotics
used to treat bacterial infections. Although antiviral medicines do
exist, there are currently none available that will treat fifth
disease. In most cases, this is such a mild illness that no
medicine is necessary.
Usually, kids with fifth disease feel fairly well and need
little home treatment other than rest. After the fever and mild
cold symptoms have passed, there may be little to treat except any
discomfort from the rash itself. If your child has itching from the
rash of fifth disease, ask the doctor for advice about relieving
discomfort. The doctor may also recommend acetaminophen for fever
or joint pain.
Complications
The majority of kids with fifth disease recover with no
complications. By the time the rash appears and while it's
present, they usually feel well and are back to their normal
activities.
However, some children with weakened immune systems (such as
those with
AIDS
or
leukemia
) or with certain blood disorders (like
sickle cell anemia
or hemolytic anemia) may become significantly ill when infected
with parvovirus B19. Parvovirus B19 can temporarily slow down or
stop the body's production of the oxygen-carrying
red blood cells (RBCs)
, causing anemia.
When a child is healthy, this slowdown of red blood cell
production usually goes unnoticed because it doesn't affect
overall health. But some kids who are already anemic can become
sick if their RBC production is further affected by the virus. The
RBC levels may drop dangerously low, affecting the supply of oxygen
to the body's tissues.
When to Call the Doctor
Call the doctor if your child develops a rash, especially if the
rash is widespread over the body or accompanied by other
symptoms.
If you're pregnant and develop a rash or if you've been
exposed to someone with fifth disease (or to anyone with an unusual
rash), call your obstetrician.
Reviewed by:
Joel Klein, MD
Date reviewed: November 2007
Originally reviewed by:
Stephen C. Eppes, MD
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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