What is the treatment for 5th disease (Erythema Infectiosum)?

Treatment of Fifth Disease (Erythema Infectiosum)

Fifth disease is a self-limited viral illness that requires only supportive care in most cases, with no specific antiviral treatment indicated for immunocompetent children and adults. 1, 2

Standard Management Approach

For Immunocompetent Patients

• Symptomatic treatment only is recommended, consisting of rest, hydration, and antipyretics for fever 1, 2
• Analgesic medications (acetaminophen or NSAIDs) for joint pain in adults, who commonly develop arthralgia affecting multiple joints symmetrically 1, 2
• No antiviral therapy is available or necessary, as the illness resolves spontaneously within 3 weeks in most cases 2
• No isolation required once the rash appears, since patients are no longer contagious at this stage 2

The rash typically evolves through three stages: the characteristic "slapped cheek" appearance, followed by a lacy reticular pattern on the trunk and extremities, then evanescence and recrudescence over approximately 3 weeks 2. By the time the rash is visible, viremia has already cleared, making the patient non-infectious 1.

For High-Risk Populations

Different management is required for three specific high-risk groups:

1. Immunocompromised Patients

• Intravenous immunoglobulin (IVIG) is the treatment of choice for chronic anemia due to persistent parvovirus B19 infection 1
• These patients cannot mount an adequate antibody response and may develop chronic infection 3

2. Patients with Hemolytic Anemia

• Red blood cell transfusions are indicated for transient aplastic crisis, which can occur in patients with sickle cell disease, hereditary spherocytosis, or other hemolytic conditions 1, 3
• Monitor hemoglobin levels closely, as the virus directly infects erythroid precursors causing temporary cessation of red blood cell production 1

3. Pregnant Women

• Serial ultrasound monitoring is essential if a non-immune pregnant woman is exposed, particularly between 14-20 weeks gestation when fetal risk is highest 4, 5
• Check maternal immune status (IgG antibodies) immediately upon exposure; if positive, no further action is needed 4
• If non-immune (IgG negative), perform serial ultrasounds every 1-2 weeks for 8-12 weeks to detect hydrops fetalis 4
• Intrauterine transfusion at a tertiary care center may be lifesaving if fetal hydrops develops 4

Diagnostic Confirmation

• Clinical diagnosis is sufficient for typical cases with the characteristic "slapped cheek" rash and lacy exanthem 1, 2
• Serum IgM and IgG antibody testing should be reserved for atypical presentations, high-risk patients, or pregnant women to confirm acute infection 1, 4
• IgM appears within 7-10 days of infection and persists for 2-3 months; IgG indicates past infection and immunity 1

Common Pitfalls to Avoid

• Do not prescribe antibiotics, as this is a viral illness and antibacterial therapy is ineffective and unnecessary 2
• Do not restrict activities once the rash appears, since the patient is no longer contagious at this stage 2
• Do not miss screening pregnant contacts, as the risk of fetal hydrops (though low at 2-10%) requires surveillance 4, 5
• Do not overlook aplastic crisis in patients with underlying hemolytic disorders who present with severe anemia and absence of reticulocytes 1, 3