PANCE Blueprint Infectious Disease (6%)

4 y/o with low-grade fever, rash on cheeks x 24h now spreading to the trunk

Patient will present as → a 4-year-old who is brought to the office by his mother. The child has had a low-grade fever, headache, and sore throat for the past week. Four days ago, he suddenly developed a bright red rash on his cheeks, which during the past two days has spread to the trunk, arms, and legs. On physical examination, the child has erythema of the cheeks and a maculopapular rash with central clearing on the trunk spreading to the extremities. There are no other significant findings.

Erythema infectiosum (also known as Fifth's disease) is a common viral exanthem observed in pediatric patients caused by parvovirus B19

• Viral prodrome sequence with low grade fever followed by slapped cheek malar rash on face and circumoral pallor for 2-4 days, followed by lacy, reticular rash (blanching) on extremities for a few weeks
• Parvovirus may cause aplastic crisis in patients with sickle cell disease and G6PD deficiency

Diagnosis is based primarily on clinical observations, history, and physical exam

• Serology: associated with enlarged nuclei with peripherally displaced chromatin
• PARVO B19-specific IgM antibodies and PCR

Observation alone

• Treatment is symptomatic
• The rash may last a few days to several weeks. It is frequently pruritic
• There is no specific antiviral used and no vaccine is available
• Parvovirus B19 is a droplet infection that is no longer contagious once the rash breaks out. Children may return to school and resume activities as symptoms allow.