Fifth disease is caused by a virus called human parvovirus B19. The illness causes the body to stop making red blood
cells for a short time. This usually does not cause a problem for an otherwise
normally healthy child or adult. But it can become a serious threat for
If a woman gets fifth disease during pregnancy and she's never had the infection before, the doctor will want to watch for certain problems in the fetus. In very rare cases, a fetus that becomes infected with parvovirus
B19 may develop severe anemia and swelling, a condition called
fetal hydrops. The mother and fetus should be closely
fetal ultrasounds to detect this condition.
When fetal hydrops is detected, the fetus may be treated with blood transfusions while in the uterus, although this is not usually
Some babies born to mothers who were infected with fifth disease
during pregnancy may also be treated with blood transfusions.
People who have blood or immune disorders
People who have blood disorders that cause anemia (such as
sickle cell disease or
thalassemia) may require
blood transfusions if a rapid worsening of existing
anemia (called transient aplastic anemia)
develops. People who
have this type of anemia can become very sick. Symptoms include fever,
lethargy, rapid heart rate, and rapid breathing.
People who have
impaired immune systems and get fifth
disease may develop a chronic parvovirus B19 infection that can lead to severe
anemia. Intravenous immunoglobulin (IVIG) may be needed to prevent a chronic parvovirus B19
infection and severe anemia.
Primary Medical Reviewer
John Pope, MD - Pediatrics
Specialist Medical Reviewer
Thomas Emmett Francoeur, MD, MDCM, CSPQ, FRCPC - Pediatrics
How this information was developed to help you make better health decisions.