Fifth disease, also called erythema infectiosum, is a viral infection caused by parvovirus B19. This virus only infects people; it's not the same type of parvovirus that dogs and cats can get.

Fifth disease mostly affects children. It often causes a bright red rash on their cheeks (sometimes called a "slapped cheek" rash).

In the United States, parvovirus B19 infections are more common in late winter, spring, and early summer. There are usually minor outbreaks of fifth disease about every 3 to 4 years.

Parvovirus B19, which causes fifth disease, can spread from person to person:

• Through respiratory droplets, such as saliva (spit), sputum, or nasal mucus. The droplets can spread when:
  • Someone who has the virus coughs and sneezes
  • You touch an item that has the virus on it
• Through blood or blood products
• From a pregnant parent to the baby during pregnancy

You are most contagious early in your infection, when you usually only have a fever or cold-like symptoms. You are not likely to be contagious after you get later symptoms such as a rash and joint pain.

About 2 out of 10 people who get a B19 parvovirus infection will have no symptoms.

But most people will get the symptoms of fifth disease, which are usually mild and can include:

• Fever
• Headache
• Cough
• Sore throat
• Rashes
• Joint pain

The "slapped cheek" rash is more common in children. They usually get the rash a few days after they first have other symptoms. The rash can then spread to the arms, legs, chest, back, and buttocks.

Adults who get fifth disease might also have joint pain and swelling (called polyarthropathy syndrome).

Sometimes the infection can cause serious health complications affecting the nerves, joints, or blood system. This is more likely to happen if you are pregnant, have a blood disorder such as anemia, or a weakened immune system.

Because of these risks to you and some possible risks to your baby, contact your health care provider if you are pregnant and:

• You show signs of fifth disease (or a "slapped cheek" rash)
• You may have been exposed to someone who has the infection

There is no routine lab test to diagnose fifth disease. Providers can often diagnose fifth disease just by seeing the "slapped cheek" rash and rashes on the body.

There is testing to show whether or not you have protection (immunity) against the B19 parvovirus or if you have had a recent infection. This test is usually not needed, but your provider may order the test if you are pregnant or at higher risk for complications of the disease.

There is no specific treatment for fifth disease. It is usually mild and goes away on its own.

To feel better, get plenty of rest. Taking acetaminophen can help with the fever and pain. Do not give aspirin to children, because it may cause Reye syndrome. This is a rare, serious illness that can affect the brain and liver.

There is no vaccine to prevent fifth disease. But you can help protect yourself and others by:

• Washing your hands often with soap and water
• Covering your mouth and nose when you cough or sneeze
• Avoiding touching your eyes, nose, and mouth with unwashed hands
• Avoiding close contact with people who are sick
• Staying home when you are sick

Most people become immune to the virus after having it once.

Centers for Disease Control and Prevention