Fifth Disease: Symptoms, Causes & Slapped Cheek Rash

What Is Fifth Disease and Why Is It Called That?

Fifth disease is a viral infection caused by parvovirus B19 that produces a distinctive bright red rash on the cheeks, giving it the nickname "slapped cheek syndrome." It was historically the fifth in a numbered list of common childhood rash illnesses, following measles, scarlet fever, rubella, and Duke's disease.

Fifth disease, medically known as erythema infectiosum, is one of the most common viral illnesses affecting children worldwide. The condition was given its name in the late 19th century when physicians created a classification system for childhood rash diseases. Before widespread vaccination programs, almost all children experienced several viral illnesses that caused distinctive skin rashes. These conditions were numbered for easy identification, and erythema infectiosum received the designation "fifth disease" in this classification system.

The virus responsible for fifth disease, parvovirus B19, was discovered in 1975 and is distinctly different from the parvoviruses that affect dogs and cats. Human parvovirus B19 can only infect humans and cannot be transmitted to or from pets. This is an important distinction that provides reassurance to families with both children and animals. The virus primarily targets rapidly dividing cells in the bone marrow, temporarily reducing the production of red blood cells, though this effect is usually not noticeable in healthy individuals.

The disease follows a predictable pattern in most cases. After an incubation period of approximately 4 to 21 days (most commonly around 14 days), the infected person develops mild cold-like symptoms including low-grade fever, headache, and general fatigue. These initial symptoms typically last several days before the characteristic rash appears. Many people who contract the virus remain completely asymptomatic, never realizing they were infected. Studies suggest that approximately 25% of infections occur without any noticeable symptoms.

Epidemiology and Prevalence

Fifth disease occurs worldwide and follows a seasonal pattern, with most cases appearing in late winter through early summer. The disease tends to occur in cyclical outbreaks every 3 to 6 years, often spreading rapidly through schools and childcare facilities. During outbreak periods, infection rates can be significantly higher than in non-outbreak years.

By adulthood, approximately 50-60% of the population has antibodies against parvovirus B19, indicating prior infection and subsequent immunity. In certain populations, particularly healthcare workers and teachers who have frequent exposure to children, the immunity rate can be even higher. Once a person has been infected with parvovirus B19 and developed antibodies, they have lifelong protection against reinfection.

What Are the Symptoms of Fifth Disease in Children?

Fifth disease in children typically begins with mild cold-like symptoms including low-grade fever, headache, and fatigue for several days, followed by the characteristic bright red "slapped cheek" rash. A lacy, net-like rash then spreads to the arms, legs, and trunk, which may come and go for 1-3 weeks.

The symptom progression in children follows a fairly predictable three-stage pattern that helps distinguish fifth disease from other childhood illnesses. Understanding this progression can help parents recognize the condition and know what to expect as the illness runs its course.

Stage 1: Prodromal (Early) Symptoms

The initial stage of fifth disease typically begins 4 to 14 days after exposure to the virus. During this phase, children may experience symptoms that resemble a mild cold or flu, including:

• Low-grade fever (usually below 38.5°C/101.3°F)
• Headache ranging from mild to moderate
• Fatigue and general malaise
• Runny nose and mild nasal congestion
• Sore throat in some cases
• Nausea and occasional diarrhea
• Body aches and muscle pain

These prodromal symptoms typically last 2 to 5 days. Importantly, this is the most contagious period of the illness. The child can spread the virus through respiratory droplets during this phase, even though the characteristic rash has not yet appeared. Many parents unknowingly send their children to school during this stage because the symptoms appear to be a common cold.

Stage 2: Facial Rash (Slapped Cheek Appearance)

After the prodromal symptoms begin to resolve, the distinctive facial rash appears. This is the hallmark feature of fifth disease and typically occurs 4 to 14 days after the initial infection. The rash presents as:

• Bright red patches on both cheeks
• Warm to the touch but usually not painful
• Well-defined borders with relative sparing of the nose, forehead, and chin
• Appearance that resembles a sunburn or slap mark

The facial rash typically lasts 2 to 5 days. By the time this rash appears, the fever has usually resolved, and the child begins feeling better overall. Crucially, children are generally no longer contagious once the facial rash develops, which means they can return to school and normal activities.

Stage 3: Body Rash

One to four days after the facial rash appears, a secondary rash develops on the body. This rash has a distinctive appearance that differs from the facial rash:

• Lacy, net-like (reticular) pattern
• Affects primarily the arms, legs, and trunk
• May be itchy in some children, though often not
• Fluctuates in intensity, appearing to fade and then return

The body rash can persist for 1 to 3 weeks, though in some cases it may last several weeks or even months. Certain triggers can make the rash temporarily more visible, including exposure to sunlight, warm baths, physical exercise, emotional stress, and temperature changes. This waxing and waning pattern can be concerning for parents, but it does not indicate worsening illness or reinfection.

How Does Fifth Disease Affect Adults?

Adults who contract fifth disease often experience different symptoms than children. While the classic facial rash may be absent, adults commonly develop joint pain and stiffness (particularly in the hands, wrists, and knees) that can persist for weeks or months. Cold-like symptoms and fatigue are also common.

When adults contract fifth disease, their experience often differs significantly from the typical childhood presentation. Approximately 40-50% of adults have not been previously infected with parvovirus B19 and remain susceptible to the virus. Those who become infected as adults may have a more prolonged and uncomfortable illness, though it remains self-limiting in most cases.

Common Symptoms in Adults

Adult fifth disease typically presents with:

• Upper respiratory symptoms similar to a cold, including nasal congestion and sore throat
• Fever, often low-grade but sometimes higher than in children
• Fatigue that may be more pronounced than in children
• Headache and general malaise
• Joint pain (arthropathy) affecting multiple joints

Notably, the characteristic "slapped cheek" facial rash often does not appear in adults. When a rash does develop, it may be more subtle and less distinctive than in children. This can make diagnosis more challenging in adult patients.

Joint Pain in Adults

The most significant difference in adult fifth disease is the high prevalence of joint involvement. Approximately 60% of adult women and 30% of adult men who contract fifth disease experience joint symptoms. This parvovirus-associated arthropathy typically:

• Affects the small joints of the hands and wrists most commonly
• May also involve knees, ankles, and feet
• Causes symmetric joint involvement (affecting both sides equally)
• Produces morning stiffness lasting more than 30 minutes
• Can persist for weeks to months, occasionally longer

The joint symptoms can be quite debilitating and may initially be mistaken for rheumatoid arthritis or other inflammatory joint conditions. However, unlike rheumatoid arthritis, the joint involvement from fifth disease does not cause permanent joint damage and will eventually resolve completely, though this may take several months.

How Does Fifth Disease Spread and How Long Is It Contagious?

Fifth disease spreads through respiratory droplets when an infected person coughs or sneezes. The illness is most contagious during the early cold-like symptom phase, before the rash appears. Once the characteristic facial rash develops, the person is typically no longer contagious and can return to normal activities.

Understanding the transmission pattern of fifth disease is crucial for preventing spread and knowing when children can safely return to school or childcare. Parvovirus B19 is a highly contagious virus that spreads efficiently through respiratory secretions, but its contagious period follows a specific timeline that differs from many other childhood illnesses.

Routes of Transmission

Fifth disease can spread through several mechanisms:

• Respiratory droplets: The primary route of transmission occurs when an infected person coughs, sneezes, or talks, releasing virus-containing droplets into the air
• Direct contact: Sharing eating utensils, drinking from the same container, or kissing an infected person
• Hand-to-mouth transmission: Touching contaminated surfaces and then touching the mouth or nose
• Blood products: Rare transmission through blood transfusions or blood products
• Vertical transmission: From pregnant mother to fetus across the placenta

The Contagious Period

One of the most important aspects of fifth disease for parents and schools to understand is the timing of contagiousness:

• Before symptoms appear: The virus can be transmitted during the incubation period, even before any symptoms develop
• During prodromal phase: The person is most contagious during the early cold-like symptom phase, before the rash appears
• After rash appears: By the time the characteristic facial rash develops, the person is generally no longer contagious

This timing presents a challenge for infection control because children spread the virus most actively when their symptoms resemble an ordinary cold. By the time fifth disease becomes recognizable through its distinctive rash, the contagious period has largely passed.

Reducing the Risk of Transmission

While it's difficult to prevent fifth disease transmission completely (since the contagious period occurs before the illness is recognizable), general hygiene measures can help reduce spread:

• Frequent handwashing with soap and water, especially before eating and after being in public places
• Avoiding sharing eating utensils, cups, and food with others
• Covering coughs and sneezes with a tissue or elbow
• Avoiding touching the face, particularly the eyes, nose, and mouth
• Staying home when feeling unwell with cold-like symptoms

There is currently no vaccine available to prevent fifth disease, though research into vaccine development continues.

When Should You See a Doctor for Fifth Disease?

Most cases of fifth disease resolve on their own without medical treatment. However, you should contact a healthcare provider if you're pregnant and exposed to fifth disease, if you or your child has a compromised immune system or blood disorder, or if symptoms are severe or persist beyond expected timeframes.

Fifth disease is typically a mild, self-limiting illness that requires no specific medical intervention. Most healthy children and adults recover completely within one to three weeks with supportive care at home. However, there are important circumstances when medical evaluation becomes necessary.

When to Seek Medical Care

Contact a healthcare provider if:

• You are pregnant and have been exposed to someone with fifth disease or develop symptoms
• You or your child has a weakened immune system (from HIV/AIDS, cancer treatment, organ transplant, or immune-suppressing medications)
• You or your child has a blood disorder such as sickle cell disease, thalassemia, or hereditary spherocytosis
• Symptoms are unusually severe or the fever is high and persistent
• The rash does not follow the typical pattern or is accompanied by other concerning symptoms
• Joint pain is severe and significantly impacts daily activities
• Symptoms persist well beyond the expected duration

How Is Fifth Disease Treated?

Fifth disease treatment is primarily supportive, as the illness resolves on its own. Rest, adequate fluids, and over-the-counter pain relievers like paracetamol (acetaminophen) or ibuprofen can help manage fever and discomfort. There is no antiviral medication for fifth disease, and antibiotics are ineffective since it's caused by a virus.

Since fifth disease is caused by a virus, antibiotics have no effect and should not be prescribed. The focus of treatment is on relieving symptoms and keeping the patient comfortable while the immune system clears the infection naturally.

Supportive Care Measures

For most cases of fifth disease, the following measures are recommended:

• Rest: Allow the body to recover, especially if fever or fatigue is present
• Hydration: Encourage plenty of fluids to prevent dehydration, especially if fever is present
• Fever and pain relief: Over-the-counter medications can help manage discomfort
• Cool compresses: May help soothe itchy or warm rash areas

Pain Relief for Children

When managing fever or discomfort in children with fifth disease:

• Paracetamol (Acetaminophen): Safe for children 3 months and older, available in child-friendly liquid forms
• Ibuprofen: Can be used in children 6 months and older, effective for both fever and pain
• Avoid aspirin: Children and teenagers under 18 should not take aspirin due to the risk of Reye's syndrome

Always follow the dosing instructions on the package and consult a healthcare provider if you're unsure about appropriate dosing for your child's age and weight.

Managing Joint Pain in Adults

For adults experiencing joint pain from fifth disease:

• NSAIDs (nonsteroidal anti-inflammatory drugs) such as ibuprofen or naproxen can help reduce joint inflammation and pain
• Paracetamol (Acetaminophen) can be used for pain relief
• Rest affected joints while maintaining gentle range of motion
• Heat or cold application may provide symptom relief

If joint pain is severe or persists for several weeks, a healthcare provider may recommend additional treatments or evaluation to rule out other conditions.

Managing Itchy Rash

If the rash causes itching, the following may help:

• Cool baths (avoiding hot water which can worsen the rash)
• Calamine lotion applied to affected areas
• Light, breathable clothing to minimize irritation
• Antihistamines if itching is significant (consult a healthcare provider for appropriate options)

What Are the Risks of Fifth Disease During Pregnancy?

Fifth disease during pregnancy can pose risks to the developing fetus, including fetal anemia and, in rare cases, hydrops fetalis (fluid accumulation) or miscarriage. The risk is highest during the first half of pregnancy. However, more than 50% of pregnant women are already immune, and most pregnancies with parvovirus B19 infection result in healthy babies.

Pregnancy and fifth disease exposure requires careful attention because parvovirus B19 can cross the placenta and infect the developing fetus. Understanding the actual risks and appropriate management can help alleviate anxiety while ensuring proper monitoring.

Understanding the Risks

When a pregnant woman who is not immune contracts fifth disease:

• The virus can cross the placenta and infect the fetus
• Fetal infection can cause anemia (reduced red blood cell production)
• In some cases, severe anemia can lead to hydrops fetalis, a serious condition involving fluid accumulation in fetal tissues
• The risk of fetal complications is highest during weeks 9-20 of pregnancy
• Overall risk of fetal loss following maternal infection is estimated at 2-10%

It's important to note that parvovirus B19 infection does not cause birth defects. The concern is specifically related to fetal anemia during pregnancy.

What to Do If Exposed During Pregnancy

If you're pregnant and have been exposed to fifth disease or develop symptoms:

1. Contact your healthcare provider promptly to discuss your exposure
2. Blood testing can determine if you're already immune (IgG antibodies) or have an acute infection (IgM antibodies)
3. If testing shows acute infection, increased ultrasound monitoring may be recommended to check for fetal anemia
4. In rare cases where severe fetal anemia develops, intrauterine blood transfusion may be performed

Reassuring Statistics

While the risks should be taken seriously, it's also important to understand the context:

• 50-60% of adults are already immune to parvovirus B19
• Even if a non-immune pregnant woman is infected, there's only about a 30-40% chance of fetal infection
• Most fetuses that are infected do not develop serious complications
• With appropriate monitoring, complications can often be detected and treated

What Are the Potential Complications of Fifth Disease?

While fifth disease is usually mild, complications can occur in certain populations. People with blood disorders may develop aplastic crisis (temporary halt in red blood cell production). Immunocompromised individuals may develop chronic infection and anemia. Pregnant women's fetuses may be at risk for fetal anemia.

For the vast majority of people, fifth disease causes no lasting problems and resolves completely. However, certain populations are at increased risk for complications and require closer monitoring.

Aplastic Crisis in Blood Disorders

Individuals with conditions that cause chronic anemia or affect red blood cell survival are at risk for aplastic crisis if they contract fifth disease. This includes people with:

• Sickle cell disease
• Thalassemia
• Hereditary spherocytosis
• Other hemolytic anemias

During aplastic crisis, parvovirus B19 temporarily stops red blood cell production in the bone marrow. In people whose red blood cells already have shortened survival, this can cause a dangerous drop in hemoglobin levels requiring hospitalization and potentially blood transfusion. The crisis is temporary and resolves as the immune system clears the virus.

Chronic Infection in Immunocompromised Patients

People with weakened immune systems may be unable to clear parvovirus B19 infection normally, leading to:

• Chronic or persistent infection
• Chronic anemia requiring ongoing treatment
• Potential need for intravenous immunoglobulin (IVIG) therapy

This includes patients undergoing chemotherapy, organ transplant recipients on immunosuppressive medications, and individuals with HIV/AIDS.

Prolonged Joint Symptoms

While not dangerous, the arthropathy (joint inflammation) associated with adult fifth disease can be quite debilitating and prolonged. Some adults experience:

• Joint pain and stiffness lasting weeks to months
• In rare cases, symptoms persisting for years
• Symptoms that may initially be confused with rheumatoid arthritis

However, unlike rheumatoid arthritis, fifth disease does not cause permanent joint damage, and symptoms eventually resolve completely.

How Can You Tell Fifth Disease from Other Rash Conditions?

Fifth disease can be distinguished from other childhood rashes by its characteristic three-stage progression: initial cold-like symptoms, followed by bright red "slapped cheek" facial rash, then lacy body rash. The facial rash spares the nose and area around the mouth, and the child typically feels well once the rash appears.

Several childhood illnesses cause rashes that may initially appear similar to fifth disease. Understanding the distinguishing features can help parents and healthcare providers make an accurate identification.

Can Children with Fifth Disease Go to School?

Yes, children with fifth disease can attend school once the rash appears. By the time the characteristic "slapped cheek" rash develops, the child is no longer contagious. Children should stay home if they have fever or feel unwell, but the presence of the rash alone is not a reason for exclusion from school or childcare.

One of the most common questions parents have about fifth disease concerns school attendance. The unique timing of the contagious period in fifth disease means that standard approaches to school exclusion differ from many other childhood illnesses.

School Attendance Guidelines

• During prodromal phase (before rash): Keep child home if they have fever or feel unwell, as with any illness
• Once rash appears: Child can return to school as they are no longer contagious
• While rash persists: Continued attendance is fine; the rash may come and go for weeks

The child should have been fever-free for 24 hours without fever-reducing medication and feel well enough to participate in normal activities before returning to school.