Does fifth disease have more complications in adults that contract the b19 human parvovirus?

Not really. People who get parvovirus b19 infection can have no symptoms or can get sick. Kids get a rash, mild fever, and/or mild cold symptoms. Adults get a rash, some joint aches, and/or joint swelling. Infected persons, with or without symptoms, recover and have immunity against re-infection. Complications can be seen in persons with chronic anemia or immunosuppression, and occasionally in pregnant women.