Parvovirus Infection In Children

Rashes are, as we know, a common complaint in the pediatric ER and one of the most difficult things to diagnose (in my opinion). Many of them look the same and distinguishing between what is a benign rash vs something sinister can always be a challenge. As we sort through the potential concerning ailments, it is also good to keep in mind the stereotypic causes of mild pediatric rashes. Recently a patient with an intermittent rash and bright cheeks brought one of these conditions to mind. Let’s take a moment to recall Parvovirus Infection in Children:

Parvovirus: What is it?

• Parvovirus B19 is a small, non-enveloped DNA virus that infects humans.
• Member of the Parvoviridae family, specifically the Erythroparvovirus genus.
• Responsible for a variety of diseases in humans, including the well-known “fifth disease” in children, but it can also lead to more severe complications in certain individuals, particularly those with compromised immune systems, or with underlying hematologic disorders.

Parvovirus: Epidemiology

• Parvovirus B19 infections occur worldwide.
• Most common in children between the ages of 5 and 15 years.
• Outbreaks typically occur in schools and daycare centers.
• In temperate climates, outbreaks are more common in the spring and fall months.

Parvovirus: Transmission

Parvovirus B19 is transmitted primarily through respiratory secretions. Other modes of transmission include:

• Vertical transmission: From mother to fetus during pregnancy, which can lead to serious complications.
• Parvovirus B19 can also be spread through contaminated blood products.
• The virus can spread easily in crowded settings like schools and daycare centers.

Parvovirus: Pathogenesis

1. Parvovirus B19 targets erythroid progenitor cells in the bone marrow, where it binds to the blood group P antigen on the cell surface and enters the host cell.
2. After entering the host cell, the virus replicates its genome and produces new viral proteins.
3. The virus mainly infects immature red blood cells (erythroblasts) and can lead to a decrease in the number of circulating red blood cells.
4. The infection causes the destruction of erythroblasts, leading to anemia.

Parvovirus B19: Presentations

• Fifth Disease (Erythema Infectiosum):
  • Children are primarily affected.
  • Early symptoms include fever, headache, and malaise, followed by a characteristic “slapped cheek” rash (bright red cheeks), and a lace-like rash on the trunk and limbs.
  • The rash often resolves in about 1-2 weeks, and worsen with exposure to sunlight and stress.

• Arthropathy
  • This affects primarily adults but can also be seen in children, though infrequently.
  • Joint symptoms may persist for weeks to months, although they are rarely debilitating

• Aplastic Crisis
  • Individuals with pre-existing hematological disorders (e.g., sickle cell disease, thalassemia) can develop an aplastic crisis when the virus temporarily halts the production of red blood cells in the bone marrow.
  • Symptoms include fatigue, pallor, and sometimes, heart failure due to severe anemia.

• Hydrops Fetalis
  • Can cause severe fetal complications if the mother is infected during pregnancy.
  • It can lead to hydrops fetalis, a condition characterized by severe fetal anemia, heart failure, and edema.
  • The virus crosses the placenta and infects fetal erythroblasts, resulting in significant fetal morbidity and mortality if left untreated.

Parvovirus: Diagnosis

In most cases, a diagnosis can be suspected based on characteristic clinical signs, such as the “slapped cheek” rash in children, but laboratory tests can confirm the diagnosis.

Laboratory Tests:

• IgM antibodies against the virus can indicate recent/present infection.
• PCR (Polymerase Chain Reaction): This is used for detecting viral DNA, particularly in cases of aplastic crisis, hydrops fetalis, or when a more definitive diagnosis is needed.
• Complete Blood Count (CBC): Can reveal anemia and reticulocytosis in cases of aplastic crisis.

Parvovirus: Treatment and Management

• Supportive Care: Most cases, including fifth disease, are self-limiting and require no specific antiviral treatment. Symptomatic treatment may include NSAIDS and acetaminophen for joint pain or fever.
• Aplastic Crisis: In individuals with underlying hematologic disorders, an aplastic crisis may require blood transfusion to replace lost red blood cells. Immunoglobulin therapy may be considered in severe cases.
• Hydrops Fetalis: Pregnant women infected with parvovirus B19 should be closely monitored. In some cases, intrauterine blood transfusions may be necessary for the fetus. Amniocentesis may be used to test for the presence of the virus in the amniotic fluid.

Moral of the Morsel

• Slapped cheek? Lacy rash? Fever? Probably Erythema Infectiosum! Supportive care. 
• Beware aplastic crisis! Patient’s with certain hematologic conditions may warrant closer monitoring
• Small but significant! Parvovirus can cause a range of diseases from mild rashes to life-threatening complications in vulnerable populations.

Resources:

Gorman, Sophie, et al. “Human Parvovirus B19 Infection: Clinical Manifestations and Diagnosis.” Clinical Microbiology Reviews, vol. 27, no. 1, 2014, pp. 110-123. https://doi.org/10.1128/CMR.00080-13.

Wright, Tessa, and Heather R. Kegley. “Parvovirus B19 Infection in Pregnancy: A Review of the Risks and Management Strategies.” Obstetrics and Gynecology Clinics of North America, vol. 42, no. 3, 2015, pp. 379-389. https://doi.org/10.1016/j.ogc.2015.04.008.

Larcher, C., et al. “Parvovirus B19 and Its Role in Human Disease.” The Lancet Infectious Diseases, vol. 8, no. 6, 2008, pp. 307-313. https://doi.org/10.1016/S1473-3099(08)70104-4.

Centers for Disease Control and Prevention (CDC). “Parvovirus B19.” CDC, 20 May 2020, https://www.cdc.gov/ncidod/dvrd/revb/viral/fifthdisease.htm.