Some common fifth disease complications experienced by adults are pregnancy complications and chronic joint pain and swelling, according to Healthline and the Arthritis Foundation. The complications are more severe in adults who have compromised immune systems, such as HIV patients or patients with diseases such as sickle cell anemia. Patients with anemia also need to be monitored, as fifth disease prevents the body from making red blood cells.
Fifth disease is especially dangerous for a pregnant woman who has no immunity to it, says the March of Dimes. The disease can lead to anemia in the baby, which leads to a condition called hydrops. This is a dangerous buildup of fluid and can lead to fetal heart failure. Other risks are miscarriage and stillbirth. Fortunately, the risk of this is low, and tests are available to monitor the baby's health. In severe cases, the anemic baby is given a blood transfusion through the umbilical cord.
Pregnant woman who are not immune to the disease should take special precautions around children and anyone suspected of having fifth disease, advises the March of Dimes. These precautions include frequent hand washing, sanitary removal of used tissues, and not sharing eating or drinking utensils.