My child's cheeks are suddenly bright red. What's causing this?
It could be fifth disease, a viral illness known as parvovirus B19 infection, erythema infectiosum, or "slapped cheeks" disease.
Despite those scary-sounding names, fifth disease is a relatively mild illness that most kids recover from with no problem. It shows up most often in preschoolers and school-age children in the spring.
Babies and adults don't often get fifth disease, but they can. Over half the people in the world have had the virus and are therefore immune to it. Babies have some immunity from the disease thanks to the antibodies they receive from their mother at birth.
Fifth disease is one of the red-rash diseases of childhood, along with scarlet fever, measles, rubella, chicken pox, and roseola. Fifth disease was the fifth of these to be identified, and it's the only one commonly identified by its number.
What are the symptoms of fifth disease?
About a week before the rash appears, your child may run a slight fever or appear to be coming down with a cold. Symptoms might include a stuffy or runny nose, a sore throat, an upset stomach, a headache, and fatigue. Other less common symptoms include swollen glands, red eyes, and diarrhea.
When the rash shows up (usually several days later), your child's cheeks will be red and look as if they've been slapped. A red rash may also appear on his trunk, arms, thighs, buttocks, hands, and feet.
© Dr. H.C. Robinson / Science Source
Sometimes the rash is itchy, but otherwise your child will probably feel fine while he has it. Rarely, a rash that looks like blisters or bruises will appear.
While the rash can last for months, it usually disappears in a week to ten days. It may reappear if your child is very warm – from a fever or on a hot day – or if he becomes very upset or active. As the rash diminishes, it sometime looks lacy.
Not every child infected with the virus will get sick. About 20 percent of infected children and adults have no symptoms at all. And while adults often feel joint pain with the disease, children rarely do.
Is this parvovirus the same one I hear about at the veterinarian's office?
No. The parvovirus that dogs and cats get immunized against is a different virus. The virus that causes fifth disease is one that affects humans. Your child can't get parvovirus B19 from an animal, and he can't give it to an animal.
Is it contagious?
Yes. Like other viruses, this one spreads by way of saliva and nasal secretions. Your child can catch it or give it to someone by sharing utensils or from coughs or sneezes.
Once your child is exposed to the virus, it can take four to 20 days (14 days is about average) before starting to feel sick. He'll be most contagious either during the incubation period (before he has any symptoms) or the week before the rash appears, when he has cold-like symptoms.
Unlike with other rash diseases such as measles and chicken pox, most children are no longer contagious by the time they have the rash. So if your child goes to daycare or school, there's no need to keep him home at the rash stage.
Should I call the doctor?
Yes, to rule out other problems. If your child does have fifth disease, there isn't much your doctor can do. Because fifth disease is a viral illness, antibiotics won't help your child get better.
If the fever lasts longer than a few days or goes higher than 103.5 degrees Fahrenheit, a different infection may be the culprit.
In an otherwise healthy child, fifth disease is usually a mild illness. But if your child has a form of chronic anemia or a weakened immune system, fifth disease will put him at risk for serious complications.
How can I treat it?
Treat the virus as you would a cold, with fluids and rest. Like most viruses, fifth disease just needs to run its course.
By the time your child has the rash, he'll probably no longer be uncomfortable, but early on you may want to ask your doctor about giving your child acetaminophen or ibuprofen for fever or other discomfort. See our charts for the correct dosage of acetaminophen or ibuprofen.
Never give a child aspirin. It can trigger Reye's syndrome, a rare but potentially fatal disease.
How can I prevent my child from catching this virus?
There's no vaccine for fifth disease. And because a person with the disease is contagious well before the rash shows up, you can't completely protect your child from fifth disease, especially if it's making the rounds at daycare or school.
You can reduce your child's chances of catching fifth disease by washing his hands – and yours – often.
Is it dangerous to be exposed to fifth disease while I'm pregnant?
It can be.
Usually a baby whose mother is exposed to fifth disease during pregnancy will be just fine (even if the mother becomes infected). But in some cases – and more often when the mother is exposed in the first half of the pregnancy – it can cause complications for the baby, like a serious form of anemia, heart failure, or death.
If you're pregnant and you know that you're immune to fifth disease because you've had it before, you have no cause for concern. But if you don't know for sure and you've been exposed, talk with your healthcare provider.
You can be tested to see whether you're immune or if you have the disease. If you do have the disease, your provider will monitor your pregnancy closely, checking your baby for complications.