What is fifth disease?
Fifth disease is a mild rash illness that occurs most commonly in children. The child typically has a "slapped-cheek" rash on the face and a red rash on the body. Occasionally, the rash may itch. Kids may also have a low-grade fever or a "cold" a few days before the rash breaks out. The child is usually not very ill, and the rash is generally gone in 7 to 10 days.

What causes fifth disease?
Fifth disease is caused by infection with human parvovirus B19. This virus infects only humans and mostly children.

Can adults get fifth disease?
Yes, they can. An adult who is not immune can be infected and either have no symptoms or develop the typical rash of fifth disease, joint pain or swelling. The joints most frequently affected are the hands, wrists, and knees. The pain and swelling usually go away in a week or two, but they may last several months.

Is fifth disease contagious?
Yes. A person with fifth disease is contagious during the early part of the illness, before the rash appears. By the time a child has the characteristic "slapped cheek" rash of fifth disease, for example, he or she is probably no longer contagious and may return to school or child care center.

How does someone get fifth disease?
The fifth disease virus is generally spread by person to person contact. The virus is spread in the spit and nasal mucus of infected persons before the rash appears, when they appear to "just have a cold." It is commonly spread with the sharing of drinking cups or silverware. In a household, as many as 50% of family members exposed to fifth disease may become infected in this way. During school outbreaks, 10% to 60% of students may get fifth disease.

How soon after infection does a person become sick?
A person usually becomes sick 4 to 14 days after being infected with the virus, but may become ill for as long as 20 days after infection.

Does everyone who gets fifth disease become sick?
No. During outbreaks of fifth disease, about 20% of adults and children who are infected with the virus do not develop any symptoms. Persons infected with the virus, however, do develop lasting immunity that protects them against infection in the future.

How is fifth disease diagnosed?
A physician can often diagnose fifth disease by seeing the typical rash during a physical exam. A blood test may also be done to look for antibodies to the virus that causes fifth disease.

Is fifth disease serious?
Fifth disease is usually a mild illness that goes away on its own among children and adults who are otherwise healthy. Joint pain and swelling in adults usually go away without long-term disability. Fifth disease may cause a serious illness in persons with sickle-cell disease or chronic anemia. The ill person may be pale, weak, and tired, and should see his or her physician for treatment. Once the infection is controlled, the anemia goes away. People who have leukemia or cancer, who are born with immune deficiencies, who have received an organ transplant, or who have human immunodeficiency virus (HIV) infection are at risk for serious illness due to fifth disease. Occasionally, serious complications may develop from fifth disease during pregnancy.

How are parvovirus B19 infections treated?
Treatment of symptoms such as fever, pain, or itching is usually all that is needed for fifth disease. Adults with joint pain and swelling may need to rest, restrict their activities, and take medicines such as aspirin or ibuprofen to relieve symptoms.

Can parvovirus B19 infection be prevented?
There is no vaccine or medicine that prevents parvovirus B19 infection. Frequent hand washing is recommended as a practical and probably effective method to decrease the chance of becoming infected. Excluding persons with fifth disease from work, child care centers, or schools is not likely to prevent the spread of the virus, since people are contagious before they develop the rash.