Fifth Disease is a viral infection affecting red blood cells. It is caused by a human parvovirus B19. Anyone can be infected, but the disease seems to occur more often in elementary school-aged children. By adulthood, more than half of all persons have had the infection. Infection leads to long-term and probably life long immunity.
Parvovirus B19 is spread by exposure to airborne droplets from the nose and throat of an infected person. People with Fifth Disease appear to be contagious during the week PRIOR to the appearance of a rash. By the time a rash appears, the infected person is no longer infectious.
One to two weeks after exposure to the virus, some children will experience a low grade fever and tiredness. By the third week, a red rash may appear on the cheeks giving a slapped cheek appearance. The rash may extend to the body and may tend to fade, then reappear over a period of weeks. Sometimes, the rash is lacy in appearance. It may be itchy. Some children may have vague signs of illness without a rash. Infection without symptoms is also common.
A specific blood test can be done to confirm the diagnosis or to show immunity, but the test is usually not necessary in healthy children. Exposure of a pregnant woman, individuals with immunodeficiency, sickle cell disease, B-thalassemia,and related red blood cell disorder should consult their doctor.
There are no proven methods to control the spread of this common disease. Exclusion from school is not recommended by the State Board of Health as individuals are considered infectious during the period of time before symptoms appear. Once the rash appears, the individual is not infectious.