What to Know About Fifth Disease

Fifth disease, also called erythema infectiosum, is a very common viral infection that most kids get in early childhood.

It got its name because it was the fifth disease that was known to cause a fever and rash.

Measles was the first.

Symptoms of Fifth Disease

Fifth disease can cause a child to look like they have slapped cheeks. Photo by Dr. Philip S. Brachman

It is caused by parvovirus B19.

Symptoms start with a red rash on your child’s cheek, giving them the appearance that they have been slapped. And that’s where fifth disease’s other name comes from – slapped cheek disease.

This slapped cheek rash is often subtle, so that many parents might think that the rash is from the sun or wind. They often don’t even consider that their child might be ‘sick’ until a few days later, when they get a pink, lacy rash on their arms and legs. Even then, they might mistake the rash for hives, poison ivy, or any number of other common childhood rashes.

Diagnosis of Fifth Disease

Unless you understand that the fifth rash can come and go, being more obvious when your child is overheated, it can be easy to see why it isn’t quickly recognized by some people. It can also be confusing because the rash could also appear on a child’s back, chest, and leg – it doesn’t have to be limited to the cheeks and arms.

And the rash, which can be itchy, can linger for weeks or even months.

While a blood test can be done, it is this pattern of symptoms that makes the diagnosis.

Most importantly, understand that fifth disease eventually does goes away without treatment. While not usually necessary, anti-itch treatments may be tried.

Can your kids go to school with fifth disease?

Fortunately, kids are not contagious while they have this rash, so they can go to school and participate in other activities. You might need a note from your pediatrician to convince folks though. They were contagious during the week before they developed the rash though, so it can be a good idea to tell people, so they can look for symptoms too.

Facts About Fifth Disease

Other things to know about fifth disease include that:

Fifth disease is caused by the parvovirus B19 virus and is most common during the spring and school outbreaks are no uncommon.
The incubation period for fifth disease is very long – up to 4 to 21 days. That means you can get this virus about 4 to 21 days after being exposed to someone else that had it, especially if you were exposed to their respiratory secretions (coughing and sneezing) just before they developed their rash.
Prodromal symptoms of fifth disease, which can start 7 to 10 days before the rash, might include a few days of mild fever, muscle aches, headache and decreased activity.
In addition to a rash, adults with fifth disease can also have joint pain and arthritis.

It is also important to know that like roseola, fifth disease can be more serious for those with immune system problems. It can also be serious for pregnant women who aren’t immune and for those with hemolytic anemia and sickle cell disease.