The clinical signs of erythema infectiosum in children start to appear soon after the incubation period and include low grade fever, headache and flu like symptoms similar to those of rhinitis. Less common symptoms include sore throat, diarrhea, swollen glands and reddish cornea. The disease is self-limited and the illness period is followed by the emerging of rash on the facial skin. The specific slapped cheek appearance of the rash is ensued by the rash spreading to trunk, limbs and the whole body. However, palms and soles are usually not affected. The rash manifests as a lacy net like appearance known as erythema exanthum. Pruritis is usually absent although some children may complain about itchiness due to the rash.
In adults, a specific manifestation of the disease is acute polyarthopathy. It is more common in women and typically persists for few days up to several months.
During the prodromal phase (a week after exposure to PV-B19), other symptoms may appear in adults as well as in children such as coryza, abdominal pain, fever, pruritis and sore throat.
The classical clinical manifestation of erythema infectiosum is usually sufficient to establish diagnosis. However, in pregnant women and in individuals indicating presence of other coexisting symptoms reassurance of correct identification of the causative organism is needed. Several tests are available to correctly identify PV-B19. Enzyme-linked immunosorbent assay (ELISA) is a specific test used to identify IgM that is produced when PV-B19 infects the host. Evaluation of the status of PV-B19 and IgM helps in confirming the diagnosis. Other diagnostic tests comprise radioimmunoassay (RIA), dot blot hybridization, polymerase chain reaction (PCR) and loop-mediated isothermal amplification. In pregnant and immunocompromised patients presenting with symptoms of hemolytic anemia and arthropathy, a complete blood count (CBC) is usually needed  . Assessment of maternal alpha-fetoprotein levels along with serial ultrasonography are required in pregnant mothers to find out whether or not the disease has affected fetal growth.
Treatment depends upon disease severeness, patient's overall immune health and presence of comorbidities.
As described earlier, the mild form of erythema infectiosum is usually a benign and self limited illness which often resolves within few weeks without major pharamcological intervention . However, symptomatic pharmacological therapy may be required in the presence of arthralgia and pruritis. Oral analgesics are usually effective in subsiding pain associated with arthralgia while oral antihistamines and topical antipruritic agents (lotions, creams, ointments) are helpful in eradicating rash and discomfort associated with pruritis. Patients are advised to apply sun protection whenever possible as sun exposure can worsen rash. Patients suffering from serious complications such as temporary aplastic anemia require hospitalization and transfusion of blood and blood products.
Erythema infectiosum is self-limited and possesses good prognosis in previously healthy, immunocompetent individuals. However, the disease does not lead to a positive outcome in patients who are immunocompromised or already suffering from reticulocytopenia, hemolytic anemia or aplastic anemia. Prolonged, uncontrolled infection in immunocompromised individuals adversely inhibits multiplication of all progenitor cells. In worst case, this may lead to bone marrow failure.
The disease can be life threatening in pregnant mothers as the virus easily crosses the placenta and exerts a cytotoxic effect in the fetus causing severe hemolytic anemia, congestive heart failure (CHF) and as a fatal complication hydrops fetalis.
Erythema infectiosum is a viral disease. The causative organism is human parvovirus B19, also known as erythrovirus b19 or simply PV-B19. The rapidly dividing erythroid cell lines are suppressed in the disease as the virus PV-B19 undergoes division in these cells . The disease is contagious and it is transmitted through respiratory secretion when a PV-B19 infected individual exhales droplets. It can also be passed from a infected mother to her fetus and parenterally through blood transfusion.
Erythema infectiosum is found in people of all races and has been reported to affect Americans, Asians and Europeans equally . The disease shows no gender predominance and can occur equally in both males and females. However, pregnant infected women may be adversely affected by the complications occurring from the disease such as arthropathy. Epidemiological studies have revealed that the incidence of the disease is increased in winter and early spring season  and the disease outbreaks rapidly after a period of approximately every 5.5 years affecting about 40% of US population. The reported year of occurrence of the last epidemic was 1998.
As described earlier, erythema infectiosum is caused by a thermostable PV-B19 virus which contains a single strand of DNA  and undergoes multiplication by incorporating its DNA in human erythroid progenitor cells . Among all erythroviruses, PV-B19 is the only pathogenic virus known. Once the virus enters the host cell and provokes an immune response, the host cell produces IgM against the virus along with the formation of immune complexes. These immune complexes are ultimately responsible for producing specific clinical signs of erythema infectiosum by settling into skin and joints of the host.
Erythema infectiosum is a contagious illness and the risk of transmission is highest before appearance of symptoms during the incubation period of the virus inside host body. The normal incubation period of the disease ranges from 4 to 21 days. Therefore, during this time period the infected individual must be kept isolated to prevent spreading the illness. Once the incubation is completed and symptoms of rash start to appear, isolation is not required any longer  . Erythema infectiosum is commonly transmitted through respiratory secretions, when infected droplets produced in saliva and mucosa are spread by breathing out, coughing or sneezing. Teachers, parents, day care workers, school children and other persons who are in close contact with the infected child can develop the disease.
Erythema infectiosum is a contagious disease, especially during the incubation phase. In the presence of an infected child in school or household, implementation of precautionary measures is required such as frequent hand sanitation and avoiding contact with a patient's respiratory secretions. Pregnant women require special precautions because a PV-B19 infection during pregnancy can adversely affect the fetus when the infection spreads through the placenta. Similarly, pregnant health care workers should not be involved in treating cases of PV-B19 infection associated with immunosuppression or temporary aplastic anemia.
Erythema infectiosum, also referred to as 'fifth disease', 'slapped cheek disease' and 'turkey slap disease' is a benign, contagious mild childhood disorder caused by the human parvovirus B19 (PV-B19). The disease is characterized by flu-like symptoms and appearance of classic slapped-cheek rash on the face and lace pattern exanthem on the body . Erythema infectiosum is among the five common childhood diseases that are accompanied by rash, hence the name 'fifth disease.' The disease particularly affects children but it can also occur in immunosuppressed adults and pregnant women. Males and females are likewise concerned by erythema infectiosum and it occurs equally among all races. The number of reported cases of the disease increases every 3-4 years.
Erythema infectiosum is a contagious disease that is communicated through inhalation of droplets from mucus and saliva of patients infected with PV-B19. The infected children are prone to spread the illness before the appearance of rash, after which the disease does not spread and patient isolation is not required. Once the erythrovirus B19 enters the host cell, it suppresses erythroid progenitor cells. Consequently, immune reaction is provoked and immunoglobulin antibodies (IgM) are produced. The antibodies can serve as marker in establishing diagnosis of erythema infectiosum in the presence of coexisting diseases. Prodromal symptoms of the disease start to appear a week following exposure to the virus and persist for 2-3 days. A 7-10 days duration devoid of symptoms is followed after which the infection proceeds to give clinical manifestation of flu-like symptoms and characteristic skin rash. Erythema infectiosum can be diagnosed by classical clinical presentation of the disease although specialized diagnostic tests and blood cultures may be required to rule out other suspected diagnoses. Mild cases of the disease typically resolve within few weeks unless complications arise that require aggressive pharmacologic treatment. When necessary, symptomatic management with antipyretics, analgesics and antipruritics may be needed along with increased fluid intake and rest.
Erythema infectiosum or 'fifth disease' is a childhood illness caused by a virus called human parvovirus B19 (PV-B19). It is a contagious disease that is transmitted from infected patients to healthy children. Erythema infectiosum is characterized by light fever, cold-like symptoms, headache and rash. These symptoms usually appear 4-14 days after the development of the infection. In the later course, slapped cheek rash appears (which is the characteristic of the disease), along with a lace-like rash on rest of the body. The rash is worsened by exposure to sunlight and may be accompanied by itchiness. The mild form of the disease presents usually as a self-limited illness that subsides after few weeks. However, in some cases pain in joints may also occur.
Erythema infectiosum particularly affects children but adults and pregnant women with weak immune system can also suffer from this disease. It is spread by breathing in droplets from saliva or mucus secretions exhaled by infected patients. If a pregnant woman is infected, the infection may be transferred to the fetus. Erythema infectiosum can be prevented by limiting contact with infected individuals and by maintaining proper hygienic practice (frequent hand washing). Parents of infected children must assure to keep them isolated from other household members in order to prevent spreading of the disease. Pregnant health care workers should also avoid treating patients infected with PV-B19, because once the disease is transmitted to the fetus, it increases the risk of causing life threatening anemia and edema in the unborn child.
Diagnosis is based on the clinical presentation of the disease and the presence of classical slapped cheek and lace-like rashes. Blood cultures are not usually needed unless the patient has a weak immune system or other illnesses are suspected.
Erythema infectiosum is a self-limiting disease and in the majority of cases symptomatic management is all that is required. Medicines for fever, pain relief, rash and itchiness are recommended. Severe cases that temporarily affect bone marrow may require the need of injecting blood or blood products.