Fifth Disease
March 1, 2010

Parents have been asking me a number of good questions about an illness called Fifth Disease. Well, let me go forth and provide some information on this condition.

Fifth Disease is quite common, and can occur throughout the year although it’s most common in winter and spring. Kids between 5 and 15 are more likely to get it, but it can also occur in infants and adults.

It is an illness caused by a virus named parvovirus B19. Once exposed to the virus, it takes about 1-2 weeks for symptoms to begin. First you will see a low grade fever and mild cold symptoms. As these start to go away over a week or so, a bright red rash on the cheeks appears – almost looking like the cheeks have been slapped. This rash spreads downward onto the trunk, arms, and legs and then disappears in approximately one week. Fifth Disease normally gets diagnosed after the rash appears when it is no longer contagious.

It is called Fifth Disease because it is part of a series of classic rashes due to infection that are described in medical texts. The good news is that it usually goes away over time without any treatment or complications.

There really are few problems associated with this disease. Rarely, a child might experience a drop in their red blood cell counts, but only if they have a weakened immune system caused by cancer or some other illness.

The other complication arises if someone is infected early in a pregnancy. This may pose some medical problems for the unborn infant like decreased red blood cells or anemia. However, this occurs in less than 5% of pregnant women usually because most of them have already been infected with this common virus and have mounted an immune response to it, which can be confirmed by a blood test.

 As for prevention, there is no vaccine for this virus, so the best way to prevent the spread of it is through good hand washing and remembering to cough on your sleeve rather than your hands. And the good news is once you have had Fifth disease, as most of us probably have by the time we reach adulthood, you cannot get it again.

 Hopefully tips like this will allow you to think more “rashionally” when it comes to knowing a bit more about the rash and fever we associate with Fifth Disease.

Lewis First, M.D., is chief of Pediatrics at Vermont Children's Hospital at Fletcher Allen Health Care and chair of the Department of Pediatrics at the University of Vermont College of Medicine. You can also catch "First with Kids" weekly on WOKO 98.9FM and on WCAX-TV Channel 3. Visit the First with Kids video archives at