Fifth Disease: The 'Slapped Cheek' Rash Explained

How fifth disease unfolds

Fifth disease typically begins with mild cold-like symptoms — low fever, runny nose, and headache — lasting a few days. These are the days when children are most contagious. A few days later the distinctive bright-red cheek rash appears, followed within days by a lacy or net-like rash on the arms, trunk, and legs 1Ref 1Centers for Disease Control and Prevention (2024).About Parvovirus B19 | Parvovirus B19 and Fifth Disease.Contagious window before rash, slapped-cheek presentation, aplastic crisis risk in sickle cell disease, and natural history of the illness.

The lacy rash can come and go over several weeks, particularly when the child is warm (after a bath or exercise) or in direct sunlight. This on-and-off appearance is a normal feature of the illness and does not mean the infection is worsening or returning.

When is a child contagious?

The contagious window for fifth disease is counterintuitive: children are most infectious during the week or so before the rash appears, when they have cold-like symptoms and viral loads in respiratory secretions are highest. Once the slapped-cheek rash shows up, most children are no longer contagious 1Ref 1Centers for Disease Control and Prevention (2024).About Parvovirus B19 | Parvovirus B19 and Fifth Disease.Contagious window before rash, slapped-cheek presentation, aplastic crisis risk in sickle cell disease, and natural history of the illness.

This means many children spread the virus before anyone realizes they are ill. Parvovirus B19 travels through respiratory secretions — coughs, sneezes, and close contact — and moves easily through households and school classrooms. Frequent handwashing and respiratory hygiene reduce but cannot fully prevent transmission.

Why fifth disease matters during pregnancy

In healthy children and adults, fifth disease is usually mild and self-limiting. However, parvovirus B19 can cause serious complications if a pregnant person is exposed for the first time, particularly in the first half of pregnancy. Infection during weeks 9–20 of pregnancy carries the highest risk of fetal complications, including severe fetal anemia, non-immune hydrops, and in some cases miscarriage or fetal loss 2Ref 2Centers for Disease Control and Prevention (2024).Parvovirus B19 in Pregnancy.Risk of fetal anemia, hydrops, and miscarriage from B19 infection during first half of pregnancy; monitoring recommendations.

If a household member or close contact is pregnant, they should notify their obstetric provider of the exposure promptly. This allows for monitoring with additional prenatal visits, blood tests, and ultrasounds. Most people who were infected with parvovirus B19 as children already have immunity and are protected — but those who are not immune should seek guidance from their provider about what monitoring is appropriate during pregnancy.

Children with sickle cell disease or similar conditions

Children with sickle cell disease, hereditary spherocytosis, or other hemolytic conditions face a distinct, serious risk from parvovirus B19. The virus temporarily suppresses red blood cell production in the bone marrow. In children whose red blood cell turnover is already accelerated due to a blood disorder, this suppression can trigger a rapid, severe anemia known as an aplastic crisis 1Ref 1Centers for Disease Control and Prevention (2024).About Parvovirus B19 | Parvovirus B19 and Fifth Disease.Contagious window before rash, slapped-cheek presentation, aplastic crisis risk in sickle cell disease, and natural history of the illness.

Recent surveillance data documented increased aplastic crises in children with sickle cell disease during periods of elevated B19 activity. Any child with a hemolytic blood disorder who may have been exposed to fifth disease should be evaluated promptly by their care team, even if they appear well initially.

Care at home for healthy children

There is no specific antiviral treatment for fifth disease in otherwise healthy children. The illness is managed with rest, fluids, and comfort measures. Acetaminophen or ibuprofen (age-appropriate doses based on weight) can help with low fever or joint discomfort. The lacy rash requires no treatment and is not itchy in most children, though some older children and adults report mild itching or discomfort.

Adults who catch parvovirus B19 — especially those who weren't infected as children — may experience significant joint pain or achiness that can persist for several weeks. This is different from the mild course typically seen in children.

Most children can return to school or childcare once they feel well, since the contagious period has typically passed by the time the rash is visible 1Ref 1Centers for Disease Control and Prevention (2024).About Parvovirus B19 | Parvovirus B19 and Fifth Disease.Contagious window before rash, slapped-cheek presentation, aplastic crisis risk in sickle cell disease, and natural history of the illness. Schools and childcare centers may have their own return policies; check with the facility if uncertain. No vaccine for parvovirus B19 is currently in routine use; the best prevention is good respiratory hygiene and frequent handwashing, though these reduce rather than fully prevent transmission.