Fifth disease: Description, Causes and Risk Factors:
Alternative Name: Erythema infectiosum.
Fifth disease is caused by a virus called parvovirus B19
(Parvovirus B19 (B19V) was first isolated in 1975 from a specimen of healthy donor blood. B19V infection occurs worldwide and can attack persons of any age. It is most often contracted in childhood; 30-60% of adults have protective IgG antibody to the virus. Infection is asymptomatic in 20-50% of persons who acquire it. Transmission is usually by respiratory secretions. The virus replicates in bone marrow. Fifth disease typically occurs in children 4-15 years of age. Sporadic outbreaks are common, and the peak incidence is during the winter and spring. After an incubation period of 4-14 days, the child develops prodromal symptoms, usually mild, consisting of headache, fever, chills, joint pains, and malaise. About 1 week later, a bright red “slapped cheek” rash appears on the face, and over the next 3-4 days the rash spreads to the rest of the body (proximal extremities, then trunk and distal extremities, including palms and soles), where it has a reticular or maculopapular appearance. Itching, if any, is slight. The rash is an immune response, heralding the appearance of IgM antibody and the end of the period of communicability. The disease typically runs a benign course, and treatment is purely symptomatic. Like certain other viruses, B19V also occasionally causes a benign exanthem known as papular-purpuric gloves-and-socks syndrome.) Infection in adults follows a different pattern: the “slapped cheek” appearance does not occur, and the rash on the trunk and limbs tends to be milder and more subtle, but 15-20% of adult patients, virtually all of them women, develop significant joint involvement. Deposition of immune complexes in joint membranes leads to sudden onset of symmetric polyarthritis, affecting particularly the metacarpophalangeal and proximal interphalangeal joints, the wrists, and the knees. Swelling may or may not occur. Pain and disability can be severe, and symptoms can persist for weeks or months, although eventual spontaneous resolution is the rule. Because B19V infects the bone marrow, most patients experience a transient decline in red blood cells, white blood cells, and platelets. Generally this is of no consequence, but occasionally it progresses to a transient aplastic crisis (TAC), in which red blood cell production virtually stops and the red blood cell count falls rapidly. The risk of this complication is much greater in sickle cell anemia, autoimmune hemolytic anemias, immunodeficiency, and pregnancy. With the formation of IgG antibody by the immune system, red blood cell formation resumes and the anemia resolves. In patients with congenital or acquired immune deficiency, however, failure to form antibody can lead to prolonged anemia. Infection in a pregnant woman has about 1 chance in 3 of being passed to the fetus and inducing a fetal aplastic crisis. This in turn can result in congestive heart failure and fetal hydrops. Spontaneous recovery is typical, but fetal death occurs in as many as 10% of cases. Fetal infection with B19V apparently does not cause congenital anomalies. Acute B19V infection can be confirmed by a rapid rise and fall of IgM antibody. Diagnosis can also be established by culturing the virus from bone marrow or by ELISA detection of the antigen in serum. The treatment of all forms of B19V infection is purely symptomatic and supportive, since specific antiviral therapy is not available. Hospitalized patients with B19V are isolated, and pregnant workers are advised to avoid contact with them. Severe anemia may require blood transfusions. When prolonged anemia results from inability to form IgM antibody, intravenous immune globulin may help).
The virus is transferred from one person to another via airborne droplets from the nose and throat, for example when coughing or sneezing. An infected pregnant woman can transfer the virus to her unborn baby.
The incubation period for parvovirus B19 is between one and three weeks and the person will be infectious for about a week before the illness actually becomes apparent. By the time symptoms are present, the person is no longer infectious. It seems to be transmitted mainly by body fluids, including droplets produced when you cough or sneeze but also including blood. Many people (adults and children) are infected with parvovirus B19 and show no symptoms whatever. However, some people with immune system problems may develop chronic parvovirus B19 infection, and may remain contagious for up to a week after the symptoms begin. Although very rare, parvovirus B19 infection can produce more severe results. These include anemia caused by hemolysis (breakdown of red blood cells). People with abnormalities in their hemoglobin, such as those with sickle-cell disease, may develop an "aplastic crisis". It is also possible for parvovirus B19 infection during pregnancy to cause "hydrops" (fluid overload and heart failure) in the developing fetus; however, this happens in less than 10% of mothers with proven parvovirus infection in the first trimester (which probably means that the risk is much less than 10%, since many infections go unnoticed). The risk of fetal death is about 2-6%, with the greatest risk in the first half of pregnancy. No one has shown that parvovirus B19 infection during pregnancy is associated with birth defects.
The illness usually clears up without complications. The rash will normally last for up to a week. It may return several times in the following weeks as a response to stress, dramatic changes in temperature or physical exertion. The swelling in the joints is also temporary, but can last longer. Fifth disease can also cause short-term anemia. The illness gives immunity which means that you can only have it once.
Pregnant women who are infected with fifth disease have a 5 percent risk of passing on the illness to their baby. If a fetus is infected with fifth disease it could lead to a miscarriage or stillbirth, but the risk is small. If the fetus is infected and becomes seriously anemic, a blood transfusion in the uterus is possible.
Because children with fifth disease are contagious prior to the onset of the classic-appearing rash, preventing the spread of this common childhood exanthem is difficult. Attentive parents can only give their children the general good advice to frequently wash their hands and to avoid the sneezes, coughs, and discarded tissues of children who appear sick.
Typical initial manifestations are nonspecific flu-like symptoms (eg, low-grade fever, slight malaise). Several days later, an indurated, confluent erythema appears over the cheeks (“slapped-cheek” appearance) and a symmetric rash appears that is most prominent on the arms, legs, and trunk, usually sparing the palms and soles. The rash is maculopapular, tending toward confluence; it forms reticular or lacy patterns of slightly raised, blotchy areas with central clearing, usually most prominent on exposed areas. The rash, and the entire illness, generally lasts 5 to 10 days. However, the rash may recur for several weeks, exacerbated by sunlight, exercise, heat, fever, or emotional stress. Mild joint pain and swelling (nonerosive arthritis) that may persist or recur for weeks to months sometimes occurs in adults.
Immunocompromised patients can develop protracted viremia (lasting 10 to 12 days), leading to severe anemia (chronic pure RBC aplasia).
Additional symptoms may include:
The diagnosis of fifth disease is made on the basis of a medical history and physical examination. When an exact diagnosis is important, the healthcare provider can order an antibody titer blood test. The diagnosis of fifth disease usually is based on clinical presentation alone, and a workup for patients with the classic presentation is not necessary.
For patients with other PV-B19-associated signs or symptoms, or for exposure in a woman who is pregnant, confirmation of infection may be helpful and can be accomplished with the following specialized tests:
IgM assays (enzyme-linked immunoassay, radioimmunoassay).
- Dot blot hybridization.
- Polymerase chain reaction (PCR).
- Loop-mediated isothermal amplification.
Tests that may be used to evaluate fifth disease may include:
- Complete blood count.
- Blood cultures.
- Cold agglutinins.
- Chicken pox antibodies.
- Rubella antibodies.
- Measles antibodies.
Since fifth disease is a mild illness, it usually does not require treatment. Home care for a child whose rash itches may include oatmeal baths or other over-the-counter bath treatments. Adolescents with joint pain may be treated with over-the-counter pain relievers such as acetaminophen (Tylenol and others) or ibuprofen (Advil, Motrin and others). Aspirin should never be given to children with fever or flu-like illness, including fifth disease, because of the risk of Reye's syndrome, a serious brain problem that develops in some children who have had certain viral illnesses and have been treated with aspirin
Children and adults with blood disorders (sickle cell anemia, hemolytic anemia), and children who have cancer or an immune deficiency, are at increased risk of serious illness as a result of fifth disease. Patients with an immune deficiency may be given intravenous immunoglobulin (IVIG) that contains antibodies against parvovirus B19.
Symptomatic relief of fifth disease may be provided using nonsteroidal anti-inflammatory drugs (NSAIDs), antihistamines, and topical antipruritics, along with plenty of fluids and rest. For an acute aplastic crisis, supplemental oxygen and blood transfusions may be necessary. Intravenous immunoglobulin (IVIG) is helpful for chronic anemia in patients who are immunocompromised. Nonsteroidal anti-inflammatory drugs provide relief for fever, malaise, headache, and arthralgia. Although the effects of NSAIDs in the treatment of pain tend to be patient specific, ibuprofen usually is the drug of choice (DOC) for initial therapy. Other options include fenoprofen, flurbiprofen, mefenamic acid, ketoprofen, indomethacin, and piroxicam.
For best treatment options consult your physician.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.