The Bottom Line

Fifth disease is a common, mild viral illness caused by parvovirus B19. It usually starts with a few days of mild cold symptoms, then produces a bright red "slapped cheek" rash on the face, followed by a lacy rash on the body. By the time the rash appears, your child is no longer contagious and can return to school. Most children feel better quickly and recover fully without any specific treatment.

What Is Fifth Disease?

Fifth disease — known medically as erythema infectiosum — gets its name from its historical ranking as the fifth of the classic childhood rash illnesses, alongside measles, scarlet fever, rubella, and roseola. It is caused by a virus called human parvovirus B19.

The illness is very common. About 1–6% of children develop fifth disease every year, with outbreaks most likely in late winter and spring. By age 5, roughly 50% of children have already been exposed to parvovirus B19, and by adulthood about 90% have immunity. Fifth disease most often affects children between 5 and 14 years old, but people of any age can catch it.

What Are the Signs and Symptoms?

Fifth disease typically unfolds in three stages:

Stage 1 — The Prodrome (Days 1–7)

Before the rash appears, your child may have mild, flu-like symptoms that can easily be mistaken for a common cold:

  • Low-grade fever
  • Headache and fatigue
  • Runny nose or sore throat
  • Mild muscle aches

This is actually the most contagious stage — the virus is at its highest levels in the bloodstream. Unfortunately, most children are spreading the virus before anyone knows they have fifth disease.

Stage 2 — The Slapped Cheek Rash (Days 7–10)

The hallmark of fifth disease appears on the face: bright red patches on both cheeks that look like the skin was slapped. The area around the mouth (perioral area) stays pale, making the cheeks stand out dramatically. As this rash develops, your child usually starts to feel better.

Stage 3 — The Body Rash (Days 10–14+)

Over the next 1–3 days, a lacy, net-like (reticular) pink rash spreads to the trunk, arms, and legs. This rash can fade and reappear — especially with heat, sun exposure, exercise, or emotional stress — sometimes for several weeks. This is normal and not a sign that the illness is worsening.

What Causes Fifth Disease?

Fifth disease is caused by human parvovirus B19, a small virus spread through respiratory droplets — the same way colds spread. Children catch it through close contact with an infected person, typically in school or daycare. The incubation period (time from exposure to symptoms) is 4–14 days, averaging about 7–10 days.

The key timing to know: your child is most contagious before the rash appears. Once the slapped cheek rash is visible, infectivity drops significantly, and your child can usually return to school.

Are There Any Complications?

For most healthy children, fifth disease is mild and self-limiting. However, parvovirus B19 can affect other parts of the body:

  • Joint pain: Children may experience achy joints (knees, ankles, hands) during the illness. This is more common and more pronounced in older children and adults, especially women.
  • Aplastic crisis: In children with underlying blood disorders such as sickle cell disease or hereditary spherocytosis, parvovirus B19 can temporarily shut down red blood cell production, causing severe anemia. These children need prompt medical attention.
  • Pregnancy risk: Parvovirus B19 can cross the placenta. In rare cases, it causes fetal anemia (hydrops fetalis) and pregnancy loss. Pregnant women exposed to fifth disease should contact their doctor.
  • Immunocompromised individuals: Children or adults with weakened immune systems may develop persistent infection and severe anemia.

How Is Fifth Disease Treated?

There is no antiviral medicine for fifth disease in otherwise healthy children. Treatment focuses on comfort:

  • Acetaminophen or ibuprofen for fever and joint aches (never give aspirin to children)
  • Plenty of fluids and rest
  • Cool baths or avoiding overheating can reduce rash flare-ups

The rash may come and go for a few weeks, but this is harmless. Most children recover completely within 1–2 weeks.

When to See a Dermatologist or Doctor

  • Your child has a known blood disorder (like sickle cell disease) and develops fifth disease symptoms — seek care promptly
  • The rash is unusually widespread, painful, or accompanied by severe symptoms
  • Your child seems very ill or the fever is high and persistent
  • You are pregnant and have been exposed to a child with confirmed fifth disease
  • Joint swelling or pain is severe or lasts more than a few weeks
  • Your child has a weakened immune system from illness or medication

Frequently Asked Questions

Can my child go back to school when the rash appears?

Yes. Once the slapped cheek rash is visible, your child is no longer considered highly contagious. Most schools allow children to return as long as they feel well enough and are fever-free.

Why does the rash keep coming back?

The lacy body rash of fifth disease can flare and fade for weeks. Heat, sunlight, exercise, and even a warm bath can temporarily bring it back. This is normal — the virus is no longer active, but the immune response causes this skin reaction. It will eventually stop.

Can adults get fifth disease?

Yes, adults who were never infected as children can get fifth disease. Adults often experience more intense joint pain and the rash may look different. About 30% of adults develop arthritis-like joint symptoms that can last weeks to months.

Should I keep my child away from pregnant relatives?

During the early, contagious phase (before the rash appears), it is wise to limit close contact with pregnant women. Once the rash is visible, the risk of spreading the virus is low. If a pregnant woman has had significant exposure, she should contact her OB-GYN.

References

  1. Paller AS, Mancini AJ. Hurwitz Clinical Pediatric Dermatology. 5th ed. Elsevier; 2016.
  2. Magoon R, Magoon K, Narang T, et al. A comprehensive overview and pathophysiology of fifth disease. Cureus. 2020;12(11):e11584.
  3. Heegaard ED, Brown KE. Human parvovirus B19. Clin Microbiol Rev. 2002;15(3):485-505.
  4. Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 6th ed. Elsevier; 2016.
  5. Naides SJ. Erythema infectiosum (fifth disease) and other human parvovirus B19 infections. J Am Acad Dermatol. 1988;21(4):736-746.

Trusted Resources

Always consult a board-certified dermatologist or your child's pediatrician for guidance on rashes and illness in children.