Pediatric Rubella in Emergency Medicine Workup

Updated: Apr 18, 2022
  • Author: Pamela L Dyne, MD; Chief Editor: Kirsten A Bechtel, MD  more...
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Laboratory Studies

The diagnosis of rubella is clinical, though seroconversion in response to rubella antigens may confirm it.

Antibodies are often present shortly after the rash appears and increase in titer during the next 2-3 weeks.

Elevated levels of immunoglobulin M (IgM) antibodies are particularly helpful findings in newborns. IgM antibodies do not cross the placenta and indicate a recent infection acquired after birth.

The rubella virus can potentially be isolated from a throat culture during the acute phase of illness, but this technique is not a practical way to establish the diagnosis.