Fifth disease is a mild rash illness that later produces slight fever and fatigue. There is also a red rash that appears on the cheeks, giving what is often called a "slapped face" appearance. The rash can extend down onto the body and may fade and reappear later. The rash may or may not cause itching.
It is generally found in children but adults may also contract Fifth disease. About fifty percent of adults have, at some point, come into contact with the virus that causes the disease, Parvovirus B19. This exposure generally causes immunity in those persons. The symptoms are same as children but in addition they suffer from joint pain and swelling or no symptoms at all when infected. Fifth disease is contagious in its first stages, before the rash develops. By the time the rash appears, the contagious stage is normally over.

How the disease spreads?
 Individuals may become infected with the parvovirus B19 by exposure to the saliva, nasal mucus or sputum of infected persons. The stage before the rash appears may appear to be the beginning of a cold, carrying many of the same symptoms. Sharing drinking glasses and eating utensils can help to spread the virus. In elementary schools, there may be Fifth disease outbreaks where over half of students contract the disease within a short period. If a pregnant woman is infected with the disease, there are usually no serious complications. Half of all women are already immune and this immunity protects them as well as their unborn children. In most cases, even if a woman has no immunity, the illness has generally mild symptoms with no complications. However, in other cases, the infection causes severe anemia in the child and the woman may miscarry or spontaneously abort. These cases are rare, however. The parvovirus has not been shown to cause any physical or mental birth defects with infants. If a pregnant woman finds that she has been exposed to the parvovirus B19, she should immediately inform her obstetrician, who may perform tests and monitor her more closely to prevent any complications.
Some people infected with parvovirus B19 develop no symptoms. Those who have been infected, however, retain lifetime immunity to the infection. Parvovirus B19 may cause complications in individuals who have sickle-cell disease or other types of chronic anemia. In these individuals, the virus can dangerously intensify the symptoms of severe anemia. The person may be ashen, weak and fatigued and should seek medical help immediately. Once the patient has been properly treated, the symptoms of anemia will subside.
Diagnosis: A blood test for antibodies to the parvovirus B19 is performed to confirm the diagnosis. Those with leukemia, cancer and those who are transplant recipients or those born with immune deficiencies are at high risk for complications.
Treatment:  Aspirin and ibuprofen is recommended to treat fever, pain or itching. Antibodies are asked in severe cases. For those with parvovirus B19 anemia, blood transfusions may be necessary.