Parvovirus B19 and Exanthematous Viral Infections

A 7-year-old girl presents with a 3-day history of fever, malaise, and a bright red facial rash that appears as if she has been slapped on the cheeks. The rash spares the nasolabial folds and oral mucosa. Over the next 2 days, a lacy, reticular rash appears on her trunk and extremities that blanches with pressure. She has mild joint pain in her knees and wrists. Her mother reports that several children in her school developed similar illness 2 weeks ago. Full blood count shows mild anemia (Hb 10.2 g/dL) with reticulocytosis. What is the most likely diagnosis?

A 28-year-old primigravida at 16 weeks of gestation presents with fever, malaise, and a lacy rash on her trunk and extremities. She has mild joint pain in her hands and knees. A few days earlier, her 6-year-old son developed a 'slapped cheek' rash at school. Serologic testing shows IgM antibodies against parvovirus B19. Ultrasound examination reveals normal fetal anatomy with no evidence of hydrops. What is the most appropriate next step in management?

Which of the following is the characteristic rash pattern seen in parvovirus B19 infection in children?