Internal Medicine

0521779407-18 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:20

Rubella 1315

■generally mild disease with minimal morbidity and mortality

(EXCEPT congenital infections; see complications below)

■lymphadenopathy common – suboccipital/posterior auricular no-

des or generalized, precedes rash by 5–10 days

■exanthem appears on face first and spreads centrifugal pattern

■rash is usually erythematous, maculopapular, discrete

■adolescent – facial rash may be confused with acne

■in adult – exanthem frequently pruritic

■rash may NOT be present (up to half may not have rash)

■joint involvement: women more than men (usually athralgic, some-

times arthritis)

■fever variable, mild if present

■occasional features; palatal petechiae, mild pharyngitis, conjunctivi-

tis,

■in utero infection may result in abortion, stillbirth and congenital

anomalies

tests

Nonspecific:

■Low WBC, thrombocytopenia can occur

Specific:

For postnatal: best method is serology

■Single serum IgM (however note false positive can occur)

■4-fold or greater change titer IgG

■EIA most available (IFA, CF, HI or neutralizing antibody) for acute

and/or convalescent titers.

■Viral isolation is possible but not practical – nasal/throat specimens

(notify lab that rubella is suspected)

For congenital;

■best method – viral isolation urine and respiratory secretions (feces

and CSF may also be suitable specimens)

differential diagnosis

■For postnatal infection;

➣Measles; rash generally more erythematous in measles than

rubella

➣Scarlet fever; rash in Scarlet fever often spares the face

➣Infectious mononucleosis (especially when ampicillin is given)

➣Enterovirus; seasonality may be helpful

■For congenital:

➣Other TORCH agents-serology/viral isolation to distinguish