Erythema infectiosum

Definition

Erythema infectiosum, commonly known as fifth disease, is a viral infection caused by parvovirus B19 that primarily affects children. It is characterized by a distinctive facial rash that gives a 'slapped cheek' appearance, followed by a lacy, reticular rash on the body. The infection is important in the context of clinically relevant DNA viruses, as parvovirus B19 is one of the few human pathogens classified under this category.

5 Must Know Facts For Your Next Test

1. Erythema infectiosum is most commonly seen in children aged 5 to 15 years and is often mild, with symptoms usually resolving without medical intervention.
2. The classic symptom is a bright red rash on the cheeks, followed by a lace-like rash on the trunk and limbs, which can be itchy but usually isn't severe.
3. In addition to the rash, individuals may experience mild fever, headache, and flu-like symptoms before the rash appears.
4. Parvovirus B19 can have serious consequences for individuals with underlying hemolytic anemia or weakened immune systems, potentially leading to complications like aplastic crisis.
5. Erythema infectiosum is primarily spread through respiratory secretions and is contagious before the rash appears, making it important for affected individuals to be aware of their potential to spread the virus.

Review Questions

• How does erythema infectiosum differ in presentation and severity between children and adults?
  • Erythema infectiosum typically presents more mildly in children, characterized by a distinctive facial rash and generally mild systemic symptoms. In contrast, adults may experience more severe complications such as arthralgia or even chronic anemia if they have underlying health conditions. While children usually recover without significant intervention, adults are at higher risk for complications due to their immune response and pre-existing health issues.
• Discuss the role of parvovirus B19 in causing both erythema infectiosum and potential hematological complications.
  • Parvovirus B19 is the causative agent of erythema infectiosum, primarily affecting erythroid progenitor cells in the bone marrow. This viral infection can lead to anemia due to its impact on red blood cell production. In healthy children, symptoms are mild and self-limiting; however, individuals with pre-existing hematological disorders are at risk for developing an aplastic crisis due to the virus's ability to cause a significant drop in red blood cell counts.
• Evaluate the public health implications of erythema infectiosum regarding its contagiousness and impact on vulnerable populations.
  • Erythema infectiosum presents notable public health challenges due to its contagious nature before the rash appears. This aspect can lead to unintentional transmission in settings like schools or daycare centers. Vulnerable populations, such as pregnant women and individuals with blood disorders, are at increased risk for severe outcomes from parvovirus B19 infections. Public health measures should focus on educating these groups about symptoms and transmission routes to mitigate outbreaks and protect those at higher risk.

Related terms

Parvovirus B19: A small, single-stranded DNA virus that causes erythema infectiosum and is known to infect erythroid progenitor cells in the bone marrow.

Rash: A change in skin color or texture, often associated with infections or allergic reactions, which is a prominent feature of erythema infectiosum.

Aplastic crisis: A severe reduction in red blood cell production that can occur in individuals with certain blood disorders, particularly those infected with parvovirus B19.