Fifth Disease: Slapped Cheek Rash, Symptoms & Treatment

What Is Fifth Disease?

Fifth disease (erythema infectiosum) is a mild viral illness caused by human parvovirus B19 that produces a characteristic bright red rash on the cheeks, followed by a lacy rash on the body. It's one of six classic childhood rash illnesses and was historically numbered fifth, hence its name.

Fifth disease earned its unusual name from medical history. Before widespread vaccination programs, nearly all children experienced six common viral illnesses that caused distinctive rashes. Doctors numbered these illnesses for easier reference, and erythema infectiosum was labeled number five on the list. The first and second diseases were measles and scarlet fever, while third disease was rubella (German measles). Fourth disease, also known as Dukes' disease, is no longer recognized as a distinct entity. Sixth disease refers to roseola infantum.

The virus responsible for fifth disease, parvovirus B19, was first discovered in 1975. This virus is specific to humans and should not be confused with canine parvovirus, which affects dogs but cannot infect people. Parvovirus B19 has an affinity for rapidly dividing cells in the bone marrow, particularly those that produce red blood cells. In healthy individuals, this temporary disruption in red blood cell production goes unnoticed, but it can cause significant problems for those with underlying blood disorders.

Fifth disease occurs worldwide and affects people of all ages, though it is most commonly diagnosed in children between 5 and 15 years old. Outbreaks tend to occur in cycles, with epidemics appearing every 3 to 6 years, typically in late winter through early summer. During outbreak years, large numbers of children in schools and daycare centers may become infected simultaneously.

How Common Is Fifth Disease?

Fifth disease is extremely common, with approximately 50% of all adults having antibodies against parvovirus B19, indicating they were infected at some point in their lives, often without knowing it. Many people experience such mild symptoms that they never realize they had the illness. During epidemic periods, infection rates in schools can reach 60% or higher among susceptible students.

The illness is highly contagious during the early phase before the rash appears, which contributes to its rapid spread in group settings. By the time the characteristic slapped cheek rash develops and the diagnosis becomes clear, the child has typically passed the most infectious period and is no longer spreading the virus to others.

What Are the Symptoms of Fifth Disease in Children?

Fifth disease in children typically begins with mild cold-like symptoms including low fever, headache, and runny nose. After several days, the distinctive bright red "slapped cheek" rash appears on the face, followed by a lacy, pink rash that spreads to the body, arms, and legs.

The clinical course of fifth disease follows a predictable pattern in most children, though symptom severity varies considerably from one child to another. Some children may have barely noticeable symptoms, while others experience more pronounced illness. Understanding the typical progression helps parents recognize the condition and respond appropriately.

Early Symptoms (Prodrome Phase)

The illness typically begins with a prodrome phase lasting several days to a week before the rash appears. During this period, children may experience mild, nonspecific symptoms that resemble a common cold:

• Low-grade fever: Temperature typically between 37.5°C and 38.5°C (99.5°F to 101.3°F)
• Fatigue and general malaise: The child may seem tired or less energetic than usual
• Headache: Mild to moderate head discomfort
• Runny nose and sore throat: Upper respiratory symptoms similar to a cold
• Mild muscle aches: General body discomfort
• Nausea: Some children experience stomach upset
• Diarrhea: Occasionally accompanies other symptoms

Many children pass through this phase with such mild symptoms that parents may not even notice their child is ill. This is also the period when the child is most contagious, which explains why fifth disease spreads so easily through schools and daycare centers before anyone realizes an outbreak is occurring.

The Classic Slapped Cheek Rash

The most distinctive feature of fifth disease is the bright red rash that appears on both cheeks, giving the appearance that the child has been slapped on both sides of the face. This rash typically appears several days after the initial cold-like symptoms and may coincide with the fever subsiding. The cheeks become intensely red, warm to the touch, and sometimes slightly raised or swollen.

The facial rash usually spares the nasal bridge, forehead, and area around the mouth, creating a characteristic pattern that helps distinguish fifth disease from other childhood rashes. Parents often describe their child as looking unusually flushed or sunburned on the cheeks alone, without similar redness elsewhere on the face.

Lacy Body Rash

Within one to four days after the facial rash appears, most children develop a secondary rash on the body. This body rash has a distinct appearance described as lacy, reticular, or net-like. It consists of pink or light red patches that form an interconnected pattern, somewhat resembling lace fabric or a fishing net.

The lacy rash typically affects:

• Arms, especially the outer surfaces and forearms
• Legs, particularly the thighs and outer leg surfaces
• Trunk, including the back and chest
• Buttocks

This body rash can fluctuate in intensity over the following weeks. It may appear to fade completely, only to return when triggered by various factors including heat, sunlight, physical activity, warm baths, or emotional stress. This waxing and waning pattern can persist for several weeks, occasionally extending to two or three months, which can be concerning for parents who may worry the illness is not resolving.

Itching and Discomfort

The rash may cause mild to moderate itching in some children, though many experience no discomfort at all. When itching occurs, it is typically more bothersome with the body rash than with the facial rash. Cool compresses and calamine lotion can help relieve itching when it occurs. The rash itself does not leave any permanent marks or scarring.

How Does Fifth Disease Affect Adults?

Adults with fifth disease often experience different symptoms than children, with joint pain being the predominant feature. The classic slapped cheek rash is less common in adults, while painful, swollen joints affecting the hands, wrists, knees, and ankles can persist for weeks or even months.

While approximately half of adults are already immune to parvovirus B19 from childhood exposure, those who contract the infection as adults often experience a different and sometimes more challenging illness than children do. Understanding these differences helps adults recognize when they may have fifth disease and what to expect during recovery.

Joint Pain and Arthritis

The hallmark of fifth disease in adults is arthropathy, or joint involvement. Unlike children who primarily develop the characteristic rash, adults frequently experience significant joint pain and swelling that can be quite debilitating. This joint inflammation typically affects multiple joints simultaneously and may include:

• Hands and fingers: Small joints often become painful and stiff
• Wrists: Commonly affected, sometimes with visible swelling
• Knees: Large joint involvement is typical
• Ankles: Walking may become uncomfortable
• Elbows: Less frequently affected but possible

The joint symptoms typically appear around the same time the rash would appear in children, approximately one to two weeks after exposure. Joint pain is often symmetrical, affecting the same joints on both sides of the body. Morning stiffness is common, and symptoms may improve somewhat with activity during the day.

Perhaps most frustratingly for adults, the joint symptoms can persist for weeks to months, occasionally lasting up to a year in some cases. This prolonged course can significantly impact daily activities, work, and quality of life. However, it's important to understand that this joint involvement does not cause permanent joint damage and will eventually resolve completely.

Rash in Adults

Adults may or may not develop the rashes seen in children. When adults do develop a rash, it tends to be:

• Less prominent and less distinctive than the childhood version
• More likely to appear as a subtle, lacy pattern on the extremities
• Less commonly featuring the bright "slapped cheek" appearance

Some adults experience only cold-like symptoms and joint pain without any visible rash, making diagnosis more challenging. Blood tests for parvovirus B19 antibodies may be needed to confirm the diagnosis in adults with atypical presentations.

Who Is at Higher Risk?

Women are significantly more likely than men to experience joint symptoms from fifth disease, with some studies suggesting the rate is two to three times higher in women. This gender disparity is not fully understood but may be related to hormonal factors that influence immune responses and inflammation.

When Should You See a Doctor?

Most cases of fifth disease do not require medical attention. However, you should consult a healthcare provider if you are pregnant and exposed to fifth disease, have a blood disorder like sickle cell disease, have a weakened immune system, or if your child has symptoms that seem severe or unusual.

Fifth disease is typically a self-limiting illness that resolves without medical intervention in healthy children and adults. However, certain circumstances warrant professional medical evaluation to ensure proper monitoring and care.

Situations Requiring Medical Attention

In most situations, a parent can confidently manage a child's fifth disease at home. The illness does not require laboratory testing for diagnosis in typical cases, as the characteristic slapped cheek rash is usually sufficient for identification. Routine pediatric visits for uncomplicated fifth disease are generally unnecessary.

Pregnancy and Fifth Disease

Pregnancy deserves special consideration regarding fifth disease. If a pregnant woman who has never had fifth disease becomes infected, there is a 5 to 10% risk of the virus crossing the placenta and affecting the developing fetus. Potential complications include:

• Fetal anemia: The virus can suppress red blood cell production in the fetus
• Hydrops fetalis: Severe fetal anemia leading to fluid accumulation and heart failure
• Miscarriage: Risk is highest when infection occurs in the first half of pregnancy

However, it's important to maintain perspective. Approximately 50% of pregnant women are already immune from previous infection and face no risk. Even among those who become infected during pregnancy, the majority have healthy pregnancies and babies. Blood tests can determine immunity status, and ultrasound monitoring can detect fetal complications if they occur.

How Is Fifth Disease Treated?

Fifth disease has no specific antiviral treatment and typically requires only supportive care. Treatment focuses on relieving symptoms: fever and pain can be managed with paracetamol (acetaminophen) or ibuprofen, while rest, fluids, and comfort measures help children feel better during recovery.

Because fifth disease is caused by a virus, antibiotics are ineffective and should not be used. The illness runs its course naturally, with the body's immune system clearing the infection over time. Treatment strategies focus entirely on making the patient comfortable while the illness resolves.

Managing Fever and Pain

When fever or discomfort occurs, appropriate over-the-counter medications can provide relief:

• Paracetamol (acetaminophen): Safe for children from 3 months of age. Follow package directions carefully based on your child's weight and age.
• Ibuprofen: Suitable for children 6 months and older. Particularly helpful for joint pain in older children and adults.

Comfort Measures for Itching

If the rash causes itching, several approaches can provide relief:

• Cool compresses: Apply cool, damp cloths to itchy areas
• Lukewarm baths: Avoid hot water, which can worsen itching and trigger rash recurrence
• Calamine lotion: Can soothe itchy skin when applied topically
• Cooling gels: Available at pharmacies for itch relief
• Loose, comfortable clothing: Reduces skin irritation
• Antihistamines: May help if itching is significant, though consult a pharmacist for age-appropriate options

General Supportive Care

Help your child recover comfortably with these measures:

• Rest: Allow children to rest as needed, though strict bed rest is not necessary
• Hydration: Encourage plenty of fluids, especially if fever is present
• Light activities: Once fever subsides, normal activities can typically resume
• Avoid triggers: Minimize exposure to heat, sun, and vigorous exercise during the rash phase to reduce flare-ups

Joint Pain Treatment in Adults

Adults experiencing joint symptoms may require more intensive pain management:

• Non-steroidal anti-inflammatory drugs (NSAIDs): Ibuprofen or naproxen can help reduce joint inflammation and pain
• Rest: Avoiding excessive joint strain during symptomatic periods
• Warm or cool compresses: Some find relief with temperature therapy on affected joints
• Gentle movement: Light activity may help prevent stiffness without exacerbating symptoms

For persistent or severe joint symptoms, healthcare providers may recommend prescription anti-inflammatory medications or refer to a rheumatologist for further evaluation and management.

How Does Fifth Disease Spread?

Fifth disease spreads through respiratory droplets when an infected person coughs, sneezes, or talks. The virus is most contagious during the early cold-like symptom phase, before the rash appears. Once the characteristic rash develops, the child is typically no longer contagious.

Understanding how fifth disease spreads helps parents make informed decisions about school attendance, contact with pregnant women, and preventive measures during outbreaks.

Transmission Routes

Parvovirus B19 spreads primarily through:

• Respiratory droplets: The main transmission route, occurring when infected individuals cough, sneeze, or talk
• Direct contact: Touching surfaces contaminated with respiratory secretions, then touching the face
• Blood transmission: Less common, but can occur through blood products or needle sharing
• Vertical transmission: From infected mother to fetus during pregnancy

The Contagious Timeline

The timing of contagiousness is counterintuitive and important for parents to understand:

This timeline explains why fifth disease spreads so easily: children are most contagious when they appear to have nothing more than a minor cold, and by the time the distinctive rash makes diagnosis obvious, they are no longer spreading the virus.

Prevention Strategies

There is no vaccine available to prevent fifth disease. Prevention relies on general hygiene practices:

• Frequent handwashing: With soap and water, especially after contact with respiratory secretions
• Avoiding sharing: Utensils, drinks, and other personal items should not be shared
• Covering coughs and sneezes: Using tissues or the elbow crook
• Surface cleaning: Regular cleaning of commonly touched surfaces during outbreaks

Because children are most contagious before they are diagnosed, preventing spread in schools and daycare centers is challenging. Exclusion policies once the rash appears are not particularly effective since the child is no longer contagious at that point.

Should Children Stay Home from School?

Children with fifth disease can return to school or daycare once they feel well enough to participate in normal activities, even if the rash is still visible. Since children are no longer contagious once the rash appears, there is no medical reason to exclude them from school based solely on the rash.

This recommendation often surprises parents who assume a visible rash means their child should stay home. However, the unusual timing of contagiousness in fifth disease means that by the time you know your child has it, the risk of spreading it has already passed.

Guidelines for School Attendance

• Stay home if: Your child has a fever or feels too unwell to participate in normal activities
• Return to school when: Fever-free for 24 hours without using fever-reducing medication AND feeling well enough for normal activities
• The rash is not a reason to stay home: It poses no contagion risk to other students

Some parents worry about their child being stigmatized for having a visible rash at school. If this is a concern, a brief note from the parent or healthcare provider explaining that fifth disease is not contagious once the rash appears may help reassure teachers and other parents.

Notifying the School

It is considerate to inform your child's school or daycare when fifth disease is diagnosed. This allows the facility to:

• Alert pregnant staff members or parents of classmates so they can seek medical advice if needed
• Monitor for additional cases in the facility
• Provide accurate information to parents who may have questions

What Happens in the Body During Fifth Disease?

Parvovirus B19 specifically targets cells in the bone marrow that produce red blood cells, temporarily stopping their production. In healthy individuals, this brief pause goes unnoticed because existing red blood cells continue functioning. However, in people with blood disorders or weakened immune systems, this can cause serious anemia.

Understanding the mechanism of parvovirus B19 infection helps explain why the illness is usually benign but can occasionally cause serious complications in certain populations.

The Infection Process

When parvovirus B19 enters the body, it follows a specific sequence:

1. Entry: The virus enters through the respiratory tract via inhaled droplets
2. Replication: The virus targets rapidly dividing cells, particularly red blood cell precursors in the bone marrow
3. Peak viremia: Virus levels in the blood peak during the prodrome phase, explaining the high contagiousness during this period
4. Immune response: The body produces antibodies that clear the virus and cause the characteristic rash
5. Resolution: The rash represents the immune system's success in fighting the infection

Why Some People Get Sicker

In most healthy children and adults, the temporary halt in red blood cell production (lasting about 7 to 10 days) causes no problems because:

• Red blood cells live approximately 120 days
• The body has ample reserves of circulating red blood cells
• Production resumes before any shortage occurs

However, certain individuals cannot tolerate even a brief interruption in red blood cell production:

• Sickle cell disease: Red blood cells have shortened lifespans (10-20 days), so any production pause quickly leads to severe anemia (aplastic crisis)
• Hereditary spherocytosis: Similarly shortened red blood cell survival times
• Thalassemia: Already compromised red blood cell production
• Immunocompromised patients: Cannot effectively clear the virus, leading to persistent infection and chronic anemia

Lifelong Immunity

After recovering from fifth disease, most people develop lifelong immunity to parvovirus B19. The antibodies produced during infection protect against future infection, which is why the illness typically occurs only once in a lifetime. This immunity also protects during future pregnancies if a woman was infected before becoming pregnant.

What Are the Possible Complications?

While fifth disease is usually mild, complications can occur in certain groups: pregnant women may experience fetal anemia or miscarriage; people with blood disorders may develop aplastic crisis (severe anemia); and immunocompromised individuals may suffer chronic infection and persistent anemia.

Understanding potential complications helps identify who needs additional medical monitoring and when to seek urgent care.

Aplastic Crisis

The most serious complication in non-pregnant individuals is aplastic crisis, a sudden, severe drop in red blood cells that occurs when parvovirus B19 halts bone marrow production in someone with an underlying blood disorder. Symptoms include:

• Extreme fatigue and weakness
• Pale skin (pallor)
• Rapid heartbeat
• Shortness of breath
• Fainting or dizziness

Aplastic crisis requires urgent medical attention and may necessitate blood transfusions. With appropriate treatment, patients typically recover fully, and the crisis resolves once the infection clears.

Pregnancy Complications

When fifth disease occurs during pregnancy, potential fetal complications include:

• Fetal anemia: The virus can cross the placenta and affect fetal red blood cell production
• Hydrops fetalis: Severe anemia leading to heart failure and fluid accumulation in fetal tissues
• Miscarriage or stillbirth: Risk is highest with infection in the first half of pregnancy

The overall risk of fetal loss following maternal infection is estimated at 2 to 10%, occurring primarily when infection happens before 20 weeks of pregnancy. Regular ultrasound monitoring can detect fetal complications, and in some cases, intrauterine blood transfusions can save affected pregnancies.

Chronic Infection in Immunocompromised Patients

Individuals with weakened immune systems may be unable to clear the virus, resulting in:

• Persistent parvovirus B19 infection
• Chronic anemia requiring ongoing transfusions
• Need for intravenous immunoglobulin (IVIG) therapy

These patients require specialized medical management and monitoring by infectious disease specialists.