Snapshot A 3-year-old girl is brought to the pediatrician’s office for a rash that began on the face and spread to the rest of her body. The rash is sometimes itchy. The girl also has a low-grade fever. She had just moved from South America to the US and had not received her childhood vaccinations. On physical exam, she has postauricular lymphadenopathy, a pink non-confluent maculopapular rash, and petechiae on her soft palate. Introduction Classification rubella virus an enveloped, single-stranded, positive-sense RNA virus icosahedral capsid a togavirus causes rubella (German 3-day measles) transmission via respiratory secretions Epidemiology incidence decreased in the US due to vaccination endemic in other parts of the world demographics any age can be affected risk factors lack of vaccination travel to or from endemic areas Pathogenesis the virus replicates in the upper respiratory tract and lymph nodes it then disseminates throughout the body can spread through the placenta to cause vertical transmission may result in miscarriage or congenital rubella syndrome Associated conditions congenital rubella syndrome blueberry muffin appearance dermal extramedullary hematopoiesis cataracts deafness congenital heart disease (pulmonary artery stenosis or patent ductus arteriosus) Prevention measles, mumps, and rubella (MMR) vaccine given over 2 doses Prognosis infection may be asymptomatic but still contagious Presentation Symptoms low-grade fever polyarthritis and polyarthralgia more common in adult females fingers, wrists, and knees are most commonly involved Physical exam lymphadenopathy before the rash postauricular lymphadenopathy is classic may also have posterior cervical and suboccipital lymphadenopathy fine, pink, non-confluent maculopapular rash starts on face and spreads to trunk and extremities may be itchy desquamates rash resolves in 3 days petechial rash on soft palate (Forschheimer spots) orchitis Studies Labs detection of rubella-specific immunoglobulin M or G detection of virus on reverse transcriptase-polymerase chain reaction Making the diagnosis based on clinical presentation and confirmed with laboratory studies Differential Parvovirus B19 infection distinguishing factors slapped cheek rash maculopapular rash on trunk and limbs that does not spread from head/neck downward Measles distinguishing factors confluent maculopapular rash coryza and Koplik spots Treatment Management approach mainstay of treatment is supportive care and prevention with vaccines Conservative supportive care indication all patients modalities anti-pyretics analgesics hydration Complications Vertical transmission to fetus congenital rubella syndrome Thrombocytopenic purpura Guillain-Barré syndrome