Fifth disease is a common childhood illness caused by parvovirus B19. It gets its name from being the fifth in a group of childhood infections that cause similar skin rashes. Most children recover fully on their own, with little or no treatment. However, fifth disease can be more serious for pregnant women, people with anemia, and those with weakened immune systems.
What Is Fifth Disease?
Doctors also call fifth disease erythema infectiosum or slapped cheek disease. The nickname comes from the bright red rash that appears on the cheeks, making a child’s face look like it has been slapped.
Fifth disease is one of five classic childhood illnesses that cause a rash. The others are measles, rubella, scarlet fever, and Dukes’ disease. Despite the dramatic-looking rash, fifth disease is usually mild and manageable for healthy children.
It is important to know that parvovirus B19 — the virus behind fifth disease — is completely different from the parvovirus that affects dogs and cats. You cannot catch fifth disease from a pet, and your pet cannot catch it from you.
Fifth Disease Symptoms to Watch For
Fifth disease develops in stages. Knowing what to expect can help you stay calm and respond appropriately.
Early Symptoms
In the first stage, most children feel generally well. However, some develop mild cold-like symptoms that last between five and ten days. These early symptoms can include:
Sore or inflamed throat
Low-grade fever
Mild digestive upset
Headache
Fatigue
Itchy skin (pruritis)
These early signs can easily be mistaken for a regular cold. As a result, many parents do not realise their child has fifth disease until the rash appears.
The Rash Stage
A few days after the early symptoms, a bright red rash appears on both cheeks. This is the hallmark sign of fifth disease. The rash gives the child that distinctive “slapped cheek” appearance.
Shortly after, the rash can spread to the arms, trunk, thighs, and buttocks. In these areas, it looks lacy, slightly raised, and pinkish in colour. The rash usually appears in the final stage of the illness.
The rash may come and go for up to three weeks. It tends to look worse when the child is exposed to heat, sunlight, or extreme temperatures. Toddlers and school-age children experience the same pattern of symptoms.
Symptoms in Adults
Adults with fifth disease often experience joint pain and swelling, known as arthralgia. This is usually the most noticeable symptom in adults. The hands, wrists, knees, and ankles are most commonly affected.
Joint discomfort can last from a few days to several weeks. In some adults, fifth disease can occur with no symptoms at all. This is called an asymptomatic infection.
How Fifth Disease Spreads
Parvovirus B19 spreads from person to person, much like the flu. It travels through respiratory droplets — for example, from coughing or sneezing — and through hand-to-hand contact.
The illness is most contagious during the week before the rash appears. Once the rash shows up, the person is generally no longer contagious. Therefore, most children with fifth disease do not need to be kept home from school once the rash has developed.
Fifth disease is more common among school-age children. Outbreaks tend to occur during late winter and early spring. However, infections can happen at any time of year. According to Health Canada, parvovirus B19 infections are widespread and affect people of all ages across the country.
Who Is at Higher Risk?
For most healthy children, fifth disease is mild. However, certain groups face a higher risk of serious complications.
Pregnant Women
If you are pregnant and exposed to parvovirus B19, contact your family doctor or midwife right away. The virus can pass from mother to unborn baby. Most pregnant women who get fifth disease deliver healthy babies. However, there is a small but real risk of serious complications for the fetus.
In rare cases, fetal infection can lead to severe anemia and a life-threatening condition called hydrops fetalis. This involves dangerous fluid buildup in the baby’s tissues and can cause pregnancy loss. The risk is highest during the first trimester.
People With Anemia
If you have sickle cell disease or another form of chronic anemia, fifth disease can trigger a sudden and severe drop in red blood cells. This is called an aplastic crisis. Prompt medical attention is essential in this situation.
People With Weakened Immune Systems
Those undergoing cancer treatment, organ transplant recipients, or people living with immune-suppressing conditions are at greater risk of a prolonged or more serious infection. Their bodies may struggle to clear the virus on their own.
For more detailed information on vulnerable populations, the Mayo Clinic’s guide to parvovirus infection offers a helpful clinical overview.
Diagnosis and Testing
In most cases, a doctor can diagnose fifth disease simply by looking at the rash. No lab tests are needed for healthy children with typical symptoms.
However, if you are pregnant or have a compromised immune system, your doctor may order blood tests. These tests check for specific parvovirus B19 antibodies. The results show whether you are immune, currently infected, or at risk.
Roughly half of all adults are already immune to fifth disease. This immunity usually comes from a mild or symptom-free infection during childhood. Depending on your test results, your doctor may recommend:
No further action, if tests confirm immunity
Additional blood work, to rule out complications like anemia
Ultrasound monitoring, if you are pregnant and recently infected
Your provincial health plan covers most of these diagnostic tests when ordered by your family doctor. If you do not have a family doctor, a walk-in clinic can also arrange initial testing and referrals.
Treatment for Fifth Disease
There is no specific antiviral treatment for fifth disease. For healthy children, the goal is to manage symptoms while the body fights the infection on its own.
Simple steps to ease discomfort include:
Rest and plenty of fluids
Over-the-counter fever reducers like acetaminophen or ibuprofen (follow age-appropriate dosing)
Antihistamines or soothing creams for itchy skin
Avoiding prolonged sun exposure, which can make the rash worse
For adults with joint pain, anti-inflammatory medications can help. In more serious cases — for example, in patients with anemia or immune suppression — medical treatment targets the specific complication rather than the virus itself. As the infection clears, symptoms typically improve on their own.
When to See a Doctor for Fifth Disease
Most cases of fifth disease do not require a doctor’s visit. However, there are situations where medical attention is important. Visit your family doctor or a walk-in clinic if:
Your child develops a fever above 38.9°C
You are unsure whether the rash is caused by fifth disease or something else
Your child has other worrying symptoms alongside the rash
You are pregnant and think you have been exposed to parvovirus B19
You have sickle cell disease or chronic anemia and develop symptoms
You are immunocompromised due to illness, cancer treatment, or organ transplant
When in doubt, always check with a healthcare provider. Early assessment can prevent complications, especially for higher-risk individuals. The Healthline overview of fifth disease also provides clear guidance on recognising warning signs.
Please note: This article is for general information only. Always speak with your family doctor or a qualified healthcare provider for advice specific to your situation.
Frequently Asked Questions About Fifth Disease
Is fifth disease contagious after the rash appears?
No. Fifth disease is most contagious in the week before the rash develops. Once the rash appears, the person is generally no longer able to spread the virus to others. This means most children with fifth disease can safely return to school once the rash shows up.
Can adults get fifth disease?
Yes, adults can get fifth disease, although about half of all adults are already immune from a past infection. In adults, the most common symptom is joint pain and swelling rather than a rash. Symptoms in adults can sometimes last several weeks.
Is fifth disease dangerous during pregnancy?
Fifth disease during pregnancy carries a small risk of complications for the unborn baby, including severe fetal anemia and, in rare cases, pregnancy loss. Most pregnant women who contract fifth disease still deliver healthy babies. However, you should contact your doctor right away if you think you have been exposed.
How long does fifth disease last in children?
The early cold-like symptoms of fifth disease typically last five to ten days. The rash that follows can come and go for up to three weeks. Overall, most healthy children recover completely within a few weeks without any specific treatment.
Can you get fifth disease more than once?
Once you have had fifth disease, your immune system builds lasting immunity to parvovirus B19. As a result, most people only get fifth disease once in their lifetime. However, people with severely weakened immune systems may not develop full immunity after infection.
Can you catch fifth disease from a dog or cat?
No. The parvovirus B19 that causes fifth disease in humans is completely different from the parvovirus that affects pets. You cannot catch fifth disease from your dog or cat, and your pet cannot catch it from you.
Key Takeaways
Fifth disease is a mild viral illness caused by parvovirus B19, most common in school-age children.
The signature sign is a bright red “slapped cheek” rash, followed by a lacy rash on the body.
The illness is most contagious before the rash appears. Once the rash develops, the child is usually no longer contagious.
Most healthy children recover on their own with rest, fluids, and symptom relief.
Fifth disease can be more serious for pregnant women, people with anemia, and those with weakened immune systems.
See your family doctor or visit a walk-in clinic if you are pregnant, immunocompromised, or have concerns about your child’s symptoms.
There is no vaccine for fifth disease, so good hand hygiene remains the best prevention.
