Neonatal Problems: Congenital Syphilis

Description

Syphilitic pregnant women who have not received therapy may transmit the infection to their foetuses at any clinical stage of their disease.
70% of all pregnant women with untreated primary syphilis, 90% of women with secondary syphilis and approximately 30% of women with latent syphilis may transmit the infection to their foetuses. In general the greater the time that has elapsed since the woman's primary or secondary infection the less likely she is to transmit disease to the foetus.

At the onset of congenital syphilis, Treponema pallidum , the bacterium responsible for syphilis, is liberated directly into the circulation of the foetus resulting in widespread dissemination. The outcome of untreated foetal infection is variable. Intrauterine death occurs in an estimated 25% of infections. Perinatal death may occur in an additional 25% of untreated infected babies.

Treatment with penicillin during pregnancy almost entirely prevents congenital syphilis in newborns and therefore the American Medical Association recommend the routine serologic screening of pregnant women at the time of the first prenatal visit as well as serologic testing and obtaining a sexual history at 28 weeks of gestation and at delivery in communities and populations in which the risk for congenital syphilis is high.

See also Sexually Transmitted Diseases in Women .

Symptoms and Signs

The signs and symptoms of congenital syphilis are arbitrarily divided into early manifestations , which appear in the first 2 years of life, and late manifestations , which appear thereafter.

Early congenital syphilis usually starts in between birth and about 3 months of life, with most cases occurring within the first five weeks of life. Because of their frequency and early appearance the changes in the bones, especially the femur and humerus, are of diagnostic value. Other symptoms include rhinitis , coryza , or snuffles. Snuffles usually occur in the first week of life, are very persistent and often bloody. A syphilitic rash, typically consisting of small spots that are dark red to copper, usually appears after 1- 2 weeks of rhinitis and is most severe on the hands and feet. As the rash fades, the lesions become coppery or dusky red.
Fissures often develop about the lips and anus. They bleed readily and heal with scarring. White mucous patches may be found on any of the mucous membranes. Ectodermal changes include exfoliation of the nails, loss of hair and eyebrows, and iritis (inflammation of the iris).

Late manifestations of congenital syphilis are the result of scarring from the early systemic disease and include involvement of the teeth, bones, eyes, and gummas in the viscera, skin, or mucous membranes. Characteristic changes of the teeth include a notched appearance on the biting edges of the upper central incisors, these are called Hutchinson's teeth. Interstitial keratitis is the most common late lesion. Bony changes include sclerosing lesions, saber shin, frontal bossing and gummatous or destructive lesions within long bones.

Diagnosis and Treatment

The characteristic symptoms provide a strong clue to the diagnosis, which can be confirmed by the examination of a sample from a tissue sample and antibody tests. The American Medical Association [ 2 ] recommends that all infants born to seroreactive mothers (i.e. tests show signs of syphilis) should be evaluated with a Rapid plasma reagin or VDRL test on their blood serum. However, the diagnosis of congenital syphilis in neonates is complicated by the transfer of maternal IgG antibodies to the foetus across the placenta. This transfer of antibodies makes the interpretation of reactive serologic tests for syphilis in infants difficult. Thus, treatment decisions often must be made based on:

1. Identification of syphilis in the mother.
2. Adequacy of maternal treatment.
3. Presence of clinical, laboratory, or radiographic evidence of syphilis in the infant.
4. Comparison of the infant's nontreponemal serologic test results with those of the mother.

Infants born to mothers who received adequate penicillin treatment for syphilis during pregnancy are at minimal risk for congenital syphilis, but they should be examined carefully and at frequent intervals until the serologic test results are negative.
Infants should also be treated if maternal treatment was inadequate, was unknown, or was given during the last 4 weeks of pregnancy, or was with drugs other than penicillin.
Treatment in the newborn also consists of penicillin.

The information in this page is presented in summarised form and has been taken from the following source(s):
1. Vanderbilt University Medical Center, Pediatric Interactive Digital Library: http://www.vanderbiltchildrens.com/
2. Journal of the American Medical Association, Women's Health Information Center - Sexually Transmitted Diseases: http://www.ama-assn.org/