Diagnosis: Erythema Infectiosum (Fifth Disease)
A 7-year-old female presenting with a classic slapped cheek facial erythema followed by a lace-like reticular rash on the trunk and extremities.
Bilateral, confluent, bright red erythema of the cheeks (slapped cheek appearance) with circumoral pallor. Reticular (lace-like) erythematous eruption on the proximal extremities and trunk, blanches on pressure and intensifies with warmth. Mild arthralgia of the knees.
One week prior to rash onset, the child had a mild upper respiratory illness with low-grade fever that resolved spontaneously. Several classmates had similar symptoms. Mother is 14 weeks pregnant and concerned about exposure.
Supportive care: the rash is self-limited and typically resolves within 1-3 weeks. Antipyretics as needed for arthralgia. Mother referred to OB/GYN for parvovirus B19 IgG/IgM testing given pregnancy. Patient no longer contagious once rash appears.
• Measles • Rubella • Drug eruption • Lupus erythematosus (malar rash) • Roseola • Scarlet fever • Viral exanthem
• Caused by Parvovirus B19 — also known as Fifth Disease • Classic "slapped cheek" appearance followed by reticular (lace-like) rash on trunk and extremities • By the time rash appears, the patient is no longer contagious • Risk in pregnancy: fetal hydrops, miscarriage (Parvovirus B19 infects erythroid precursors) • In patients with chronic hemolytic anemias (sickle cell): can cause aplastic crisis • Adults: may present with symmetric polyarthropathy (especially women) • Diagnosis: Parvovirus B19 IgM antibodies • Self-limited — no antiviral treatment needed in immunocompetent patients
Tags: viral exanthem, parvovirus B19, pediatric, pregnancy concern, self-limited