Fifth Disease (Slapped Cheek Syndrome): What the Red Face Means

What Is Fifth Disease?

Fifth disease — medical name: erythema infectiosum — is a viral illness caused by human parvovirus B19. It was historically called "fifth disease" because it was the fifth on a list of classic childhood rash illnesses identified in the late 1800s. It is very common, occurring most often in children ages 5-14 years, and tends to circulate in schools and daycares in late winter and spring.

Most adults are already immune — studies suggest 60-70% of adults have had parvovirus B19 at some point in childhood and are protected from getting it again. When susceptible adults do catch it, the illness can be slightly more uncomfortable, with joint pain being more prominent than in children.

What Does It Look Like?

Fifth disease has a distinctive, hard-to-miss appearance that unfolds in stages:

Stage 1 — Prodrome (days 1-7): The illness starts like a mild cold. Your child may have a low fever, stuffy or runny nose, mild headache, and just feel generally "off." This phase is actually when the child is most contagious — before any rash appears.

Stage 2 — Slapped cheek rash (days 7-10): Then, seemingly out of nowhere, both cheeks turn fiery red. The redness is intense and has sharp borders, with the area around the mouth staying pale by comparison. This is the dramatic "slapped cheek" appearance. At this point, the child typically starts to feel better — the fever resolves as the rash appears.

Stage 3 — Lacy body rash (days 10-14+): Within 1-3 days of the cheek rash, a different type of rash appears on the trunk and spreads to the arms and legs. This rash has a beautiful lacy or net-like pattern — like rose-colored fishnet against the skin. It typically does not itch. This body rash may fade and reappear over several weeks, especially when the child is warm (from a bath, exercise, or sun exposure) or emotionally stressed.

How Does It Spread?

Fifth disease spreads through respiratory droplets — the same way colds spread. An infected person breathes, coughs, or sneezes, and the virus spreads to nearby people. It can also spread through blood transfusions or from a pregnant mother to her baby. The key timing issue: children are contagious before the rash appears, during the mild cold-like phase. Once the distinctive slapped cheek rash shows up, they are generally no longer contagious through the air. This means many children return to school while they still look visibly rashed but are no longer spreading the virus.

Does My Child Need Treatment?

No specific antiviral treatment exists for fifth disease, and none is needed for healthy children. Management is entirely supportive:

• Acetaminophen or ibuprofen for fever or joint discomfort (ibuprofen is fine for fifth disease, unlike chickenpox).
• Keep your child hydrated.
• The lacy body rash may look alarming when it reappears after a warm bath — reassure yourself that this is normal and expected.
• Most children can return to school once the rash has appeared, since they are no longer contagious at that point.

The Important Exception: Pregnancy

While fifth disease is harmless for healthy children and most adults, parvovirus B19 infection during pregnancy deserves attention. The virus can cross the placenta and infect the developing baby. In most cases, this causes no harm. However, in a small number of pregnancies — particularly during the first half of pregnancy — the infection can cause fetal anemia (low red blood cells), which can lead to a condition called hydrops fetalis (fluid accumulation) in the fetus. This is uncommon but serious when it occurs. If a pregnant person is exposed to fifth disease, they should contact their obstetrician promptly for monitoring and guidance.

Joint Pain and Other Symptoms

Some children — and more commonly adolescents and adults — develop joint pain and swelling (arthritis-like symptoms) with fifth disease. In children this is mild and brief. In adults, particularly women, joint symptoms can be more pronounced and occasionally last for weeks. These joint symptoms are temporary and do not cause lasting damage.

When to See a Doctor

• You are pregnant and have been exposed to someone with fifth disease — contact your obstetrician promptly.
• Your child has a blood disorder (like sickle cell disease) or a weakened immune system — parvovirus B19 can cause more severe anemia in these children and needs close monitoring.
• Joint pain is severe or lasts more than a few weeks.
• Your child seems very unwell, has a high persistent fever, or develops any unusual symptoms alongside the rash.
• You are unsure whether the rash is fifth disease or something else.

When can my child go back to school?

Once the slapped cheek rash appears, your child is generally no longer contagious — that's actually good news. Most pediatricians and schools allow children to return to school when they feel well enough, even while the rash is visible. Check with your school's specific policy, but there is typically no need to keep your child home once the rash has appeared.

My child's rash keeps coming and going. Is that normal?

Yes — this is one of fifth disease's most characteristic features. The lacy body rash can fade and reappear repeatedly over days to weeks, often triggered by heat, exercise, sun exposure, or emotional stress. This is completely normal and does not mean your child is getting worse or becoming contagious again. The rash will eventually stop returning, usually within 2-4 weeks.

My child was tested and came back positive for parvovirus B19 IgG. What does that mean?

A positive IgG means your child has been infected with parvovirus B19 at some point in the past and now has immunity. They are very unlikely to get fifth disease again. If the IgM antibody (which indicates a recent infection) is also positive, it means the current illness is likely fifth disease. Your doctor can help interpret the results in context.

Can fifth disease affect my child's blood?

In healthy children with normal immune systems, fifth disease does not cause significant blood problems. However, in children with conditions that cause rapid red blood cell breakdown — like sickle cell disease, hereditary spherocytosis, or thalassemia — parvovirus B19 can temporarily stop red blood cell production, causing a sudden, severe drop in hemoglobin called aplastic crisis. This is a medical emergency. If your child has one of these blood conditions and is exposed to fifth disease, contact their doctor immediately.

Trusted Resources

• CDC: Parvovirus B19 and Fifth Disease
• American Academy of Dermatology
• HealthyChildren.org: Fifth Disease (AAP)

Always consult a board-certified dermatologist for diagnosis and treatment recommendations specific to your child's condition.