Congenital syphilis laboratory findings
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalsang Dolma, M.B.B.S.[2]
Congenital syphilis Microchapters |
Diagnosis |
Treatment |
Case Studies |
Congenital syphilis laboratory findings On the Web |
American Roentgen Ray Society Images of Congenital syphilis laboratory findings |
Risk calculators and risk factors for Congenital syphilis laboratory findings |
Laboratory Findings
Serology
The diagnosis of congenital syphilis is complicated by the transplacental transfer of maternal nontreponemal and tre-ponemal IgG antibodies to the fetus. This transfer of antibodies makes the interpretation of reactive serologic tests for syphilis in infants difficult.
All infants born to mothers who have reactive nontreponemal and treponemal test results should be evaluated with a quantitative nontreponemal serologic test (RPR or VDRL) performed on infant serum because umbilical cord blood can become contaminated with maternal blood and could yield a false-positive result. Conducting a treponemal test (i.e., TP-PA or FTA-ABS) on a newborn’s serum is not necessary. No commercially available immunoglobulin (IgM) test can be recommended.
Dark Microscopic Examination
All infants born to women who have reactive serologic tests for syphilis should be examined thoroughly for evidence of congenital syphilis (e.g., nonimmune hydrops, jaundice, hepatosplenomegaly, rhinitis, skin rash, and/or pseudoparalysis of an extremity). Pathologic examination of the placenta or umbilical cord by using specific fluorescent antitreponemal antibody staining is suggested. Darkfield microscopic examination or DFA staining of suspicious lesions or body fluids (e.g., nasal discharge) also should be performed.