Fifth Disease: An Alarming Name for a Common Childhood Illness

The call comes in from your child’s daycare center or school: “It looks your little Mia has Fifth Disease,” a voice calmly explains. Oh no, you think, imagining a terribly unwell child, perhaps even an ER visit. You race to pick her up, your mind whirling. Fifth Disease? Where did she get it from? How bad is it?

Fifth Disease is an alarming name for a what is actually a very common childhood viral illness. It was the fifth rash and fever illness identified, after measles (once called First Disease), scarlet fever (Second Disease), rubella (Third Disease), and the controversial Fourth Disease, which may have been a form of Staphylococcus aureas. Fifth Disease is the only rash-causing childhood illness that still retains its old numerical name. (And in case it ever comes up on trivia night, Sixth Disease is now known as roseola.)

Fifth Disease is generally harmless. It is caused by parvovirus B19, for which there is currently no human vaccine. The most common symptoms of Fifth Disease are fever, runny nose, headache, body and muscle aches, and a tell-tale facial rash that is sometimes called “slapped cheek” syndrome. This is because the virus often causes the child to have bright red cheeks with pale skin around their mouth. Some children will also develop a lacy or bumpy rash on their chest, abdomen, and back as their bodies fight off the viral infection.

While the “slapped cheek” phase of Fifth Disease looks alarming, the illness is likely no longer contagious when this symptom appears. It is most infectious when the child displays what appear to be the symptoms of the start of a common cold, such as a runny nose. Parvovirus B19 is communicated through saliva and mucus. This explains why it often spreads like wildfire at childcare and preschool facilities whose tiny inhabitants are not known to cover their nose and mouths when they cough and sneeze, wash their hands often with soap and water, and keep their hands away from their mouths, noses, and eyes.  

The majority of people come down with Fifth Disease during childhood and retain at least some immunity to it for the rest of their lives. However, Fifth Disease is transmissible to adults who have weakened immune systems or have never come down with the virus. Symptoms are usually more mild in children than in adults, who can develop painful and swollen joints in response to the viral infection. This joint pain, called polyarthropathy syndrome, may last for a week to a month or longer.

While there is no medication made specifically to treat parvovirus B19, its symptoms can be relieved with over-the-counter meds. Check in with your healthcare provider about the correct dose and use of acetaminophen or ibuprofen for you or your child. These medications can reduce the fever, aches, and pains associated with Fifth Disease. As with any viral infection, make sure the patient, big or small, gets plenty of rest and fluids to prevent dehydration.  

If the virus is causing you or your child to itch, try dabbing the skin with calamine lotion. You may also wish to apply well-wrapped ice packs or cool, wet cloths to soothe the skin. If the itching is truly bothersome, ask your doctor if it would be appropriate to use an antihistamine like Benadryl for a day or two. Children’s Liquid Benadryl and similar generics can be used to provide relief from itching for children as young as two. The antihistamine’s most common side effect is drowsiness, but that may be a small price to pay for relief from rash-related misery.

For the average, generally healthy child or adult, Fifth Disease should resolve on its own within as little as a few days. There are only two cases in which Fifth Disease could be cause for concern. First, parvovirus B19 slightly increases the risk of miscarriage for women who are infected during the first trimester. A simple blood test can determine if the mother-to-be is immune or has recently been exposed to the virus. Second, parvovirus B19 can cause a severe, life-threatening sudden anemia in children and adults who have sickle cell or any other hemolytic anemia, or who suffer from an immune deficiency disorder. Anyone with these risk factors who believes that they may have been exposed to Fifth Disease should see their healthcare provider.