Occasionally, the rash may itch. The child is usually not very ill, and the rash resolves in 7 to 10 days. Once a child recovers from parvovirus infection, he or she develops lasting immunity, which means that the child is protected against future infection. An adult who has not previously been infected with parvovirus B19 can be infected and become ill, and develop a rash, or joint pain or swelling, or both. The joint symptoms usually resolve in a week or two, but they may last several months.
Fifth disease is usually a mild illness.
It resolves without medical treatment among children and adults who are otherwise healthy. Joint pain and swelling in adults usually resolve without long-term disability. I've recently been exposed to a child with fifth disease. Usually, there is no serious complication for a pregnant woman or her baby because of exposure to a person with fifth disease. Even if a woman is susceptible and gets infected with parvovirus B19, she usually experiences only a mild illness.