An individual will be contagious as soon as they are exposed to the disease, but will not show any symptoms for, in most cases, at least two weeks. However, symptoms generally resolve without treatment in about one further week.
The most usual presentatiion of the virus is Fifth Disease, which causes spotting on the body that resembles the flushing caused by slapping. Another common presentation, particularly in adults, is joint pain that usually responds to analgesics.
The presence of the virus usually leads to the body ceasing to produce red blood cells. In an otherwise healthy patient, this is usually not a concern. However, in immunocompromised patients, the virus can lead to chronic anemia. Treatment with erythropoetin and immunoglobulin can be helpful in such cases. In patients with a history of a red blood cell disease, such as sickle cell anemia, the red blood cell count can crash, requiring a transfusion.