Fifth disease is viral illness that most kids recover from quickly and without complications. Also called erythema infectiosum, it's caused by parvovirus B19. It's especially common in kids ages 5 to 15.
Fifth disease causes a distinctive red rash on the face that makes a child appear to have a "slapped cheek." A few days later, the rash spreads down to the trunk, arms, and legs. It usually lasts 1 to 3 weeks.
In older kids and adults, fifth disease can cause joint swelling and pain that can last from weeks to months and, very rarely, years.
Signs and Symptoms
Fifth disease begins with a low fever, headache, and mild cold-like symptoms (like a stuffy or runny nose). These symptoms pass, and the illness seems to be gone until the rash appears a few days later. Kids younger than 10 are most likely to get the rash.
The bright red rash usually starts on the face. Then, red blotches (usually lighter in color) appear on the trunk, arms, and legs. After a few days, the rash, which can be itchy, takes on a lacy net-like look.
In the time that it takes for the rash to completely clear, it may seem to get worse before it finally fades away.
Sometimes fifth disease also can cause swollen glands, red eyes, sore throat, diarrhea, and rarely, rashes that look like blisters or bruises. Joint swelling or pain (often in the hands, wrists, knees, or ankles) can sometimes happen, especially in adults and older teens.
Is Fifth Disease Contagious?
Yes. Because the rash is due to an immune system reaction that happens after the infection has passed, someone with fifth disease is most contagious before the rash appears. Kids usually don't spread the infection once they have the rash.
Can Fifth Disease Be Prevented?
There is no vaccine to prevent fifth disease, and no real way to prevent spreading the virus because a person usually isn't contagious by the time the rash appears.
Washing hands well and often is always a good idea because it can help prevent the spread of many infections.
Doctors can usually diagnose fifth disease by seeing the distinctive rash on the face and body. If someone doesn't have the rash but does have other symptoms, the doctor may do blood tests to see if they're caused by fifth disease.
How Is Fifth Disease Treated?
Fifth disease is caused by a virus, so can't be treated with antibiotics (antibiotics kill bacteria, not viruses). In most cases, this is a mild illness that clears up on its own, so no medicine is needed.
Usually, kids with fifth disease feel OK and just need to rest. After the fever and mild cold symptoms are gone, there may be little to treat except any discomfort from the rash.
If your child's rash is itchy, ask the doctor for advice about easing discomfort. The doctor may also recommend acetaminophen for a fever or joint pain. Do not give aspirin to your child, as it has been linked to a rare but serious illness called Reye syndrome.
Fifth disease might cause some children with weakened immune systems (such as those with AIDS or cancer) or with certain blood disorders (like sickle cell disease or hemolytic anemia) to become ill. The virus that causes it (parvovirus B19) can temporarily slow down or stop the body's production of oxygen-carrying red blood cells (RBCs). This can lead to severe anemia, which needs to be treated in a hospital.
Parvovirus B19 infection during a woman's pregnancy may cause problems for the fetus, especially during the first half of the pregnancy.
When to Call the Doctor
Call the doctor if your child develops a rash, especially if the rash is widespread over the body or accompanied by other symptoms, like fever, cold symptoms, or joint pain.
If you're pregnant and develop a rash or if you've been exposed to someone with fifth disease (or to anyone with an unusual rash), call your health care provider.