Congenital syphilis is a potentially lethal disease caused by Treponema pallidum infections occurring during intrauterine development. Skin, mucosal and bone lesions are characteristic for congenital syphilis that may be further complicated by CNS symptoms. Children at high risk and confirmed cases should be treated with penicillin.
About two thirds of all children suffering from CS are born without any symptoms. The disease is often detected during routine screenings.
The first symptoms may appear weeks, even a few months after birth. They include skin lesions such as blisters and copper-colored rash on palms and soles, papules in face and lower abdomen and petechiae. Children often develop a purulent rhinitis and parents frequently report their children to snuffle. Of note, nasal discharge and skin lesions are highly contagious. A clinical examination may further reveal enlargement of lymph nodes, liver and spleen. Hepatomegaly is indeed the most common finding in CS and is usually associated with altered results of serum liver enzymes. More severe symptoms such as pneumonia, hemolytic anemia, thrombocytopenia and less commonly leukocytosis may be observed. Neurological symptoms may be present and consist in hydrocephalus, meningitis, seizures and consecutive mental retardation. Alterations in cerebrospinal fluid (CSF) composition may be found. Physical development may also be retarded.
When children affected by CS reach the age of half a year, they may develop osteochondritis. It may lead to pseudoparalysis and is usually not detectable in younger children . This condition mainly affects the long bones of the limbs as well as the ribs and therefore strongly impairs the child's movements. Bone lesions matching with chondroepiphysitis, ostitis or periostitis are detectable in radiographic images and are of great diagnostic value because they can indeed be found in children who show hardly any additional signs of CS .
Clinical symptoms are different in children developing late CS, that is who manifest symptoms after reaching the age of two. Ulcerative lesions in mucosa of nose and hard palate are common, as are periostal lesions resulting in leg and head deformations (saber shins, skull bossing). The nervous system may be affected, but symptoms are rare. Tabes dorsalis and paresis as well as progressive loss of hearing due to damage to the eighth cranial nerve may possibly be observed. The eyes may suffer from interstitial keratitis, consecutive corneal scarring, but also from optic atrophy leading to blindness. Tooth deformities such as Hutchinson incisors and mulberry molars are as characteristic for late CS as perioral fissures.
Maternal serum is routinely screened in early and late pregnancy and at delivery and positive results are generally the first indication of CS. Nontreponemal and consecutive treponemal serum tests of the neonate may further confirm suspected CS. Those serum tests should not be carried out with cord blood due to little sensitive and specific results. Positive results should definitely prompt a thorough examination of the neonate for skin and mucosal lesions. Possibly detected lesions, the umbilical cord and the placenta should be further examined by darkfield microscopy and immunohistochemically. Characteristic pathological alterations may be found in all those tissues. CS can be confirmed if spirochetes are detected in those samples  . Negative results do not rule out CS.
Infants and children developing symptoms of CS should also be thoroughly examined. A blood screen including liver function tests should be carried out as well as CSF analysis. Further neurologic testing may be indicated and comprise neuroimaging, brain stem and ophthalmologic tests. The long bones should be checked for signs of inflammatory alterations by means of radiographic imaging.
In some cases, CS manifests more than two years after birth. In order to diagnose CS, the child's and mother's medical history have to be taken into account as well as the results of a clinical examination and serologic tests. Hutchinson incisors, interstitial keratitis and eighth cranial nerve deafness are diagnostic for CS.
Even if CS cannot be confirmed, children at high risk of infection or those developing symptoms should be treated accordingly. This especially applies to neonates who often do not show any symptoms or only unspecific signs of illness .
The treatment of choice is penicillin. After successful treatment, nontreponemal tests should yield negative results. Treponemal tests, however, are based on the presence of antibodies and remain positive even after elimination of the pathogen .
The therapy of choice equals the treatment administered in confirmed cases and consists in i.v. administration of 50,000 units aqueous crystalline penicillin G per kg of body weight, every 12 hours during the first week of life and every 8 hours thereafter for a total of 10 days. An alternative therapy is i.m. administration of 50,000 units procaine penicillin G per kg of body weight, once a day and for 10 days. In order to eliminate all causative pathogens, continuous treatment is necessary. Thus, the whole treatment has to be repeated if more than one day is missed.
Treatment is strongly recommended for neonates at high risk of infection although they may not show CS symptoms at birth. Neonates are considered at high risk if their mother suffers from untreated syphilis, if treatment has not been appropriate or was carried out with unknown drugs. If there's a sudden increase in the maternal antibody titer, a relapse has to be suspected and the child is also considered at high risk. In case a full treatment is not an option for neonates at high risk, i.m. administration of a single dose of 50,000 units of benzathine penicillin per kg body weight may be an alternative only if the mother is clinically well, does not show any signs of infection and the child will be monitored as closely as possible. This regimen may also be applied as a precaution to neonates who are not at high risk because their mother has been adequately treated.
The treatment is slightly different for children who are diagnosed after four weeks of age or who develop late CS. While drug, single dose and time frame are equal to those applied in early CS (50,000 units of aqueous crystalline penicillin G per kg body weight over 10 days), i.v. applications have to be carried out every 4 to 6 hours. This increase in frequency of administration and therefore of overall dose is due to the risk of neurosyphilis in this group of patients . A single dose of benzathine penicillin G may be administered as described above after completion of therapy. Similarly to neonates being born by adequately treated mothers, asymptomatic infants or children may be preventively treated with i.m. applications of benzathine penicillin G (50,000 units per kg of body weight, i.m., once a week for three weeks). For treatment of interstitial keratitis, an ophthalmologist should be consulted. It usually consists in corticosteroids and atropine.
Prognosis strongly depends on time passed between maternal infection and pregnancy. Because syphilis is considered to be much more contagious in the primary stage, a condition that is already attenuated but still present in the secondary stage, it is particularly unfavorable if the infection of the mother takes place a short time before or during pregnancy. On the other hand, longer times between maternal infection and pregnancy generally improve the outcome.
Untreated primary or secondary stage syphilis during pregnancy may lead to neonatal death (14%), stillbirth (25%) or CS (41%). The remaining 20% of infants are not infected and may be born healthy. If the infected mother did already pass these early stages of syphilis, which generally means that two years have passed since infection, these numbers reduce to 9%, 12% and 2% for neonatal death, stillbirth and CS, respectively. Three out of four children are born healthy . Similar numbers have been reported elsewhere .
CS is an infectious disease caused by Treponema pallidum, a spirochete bacterium transmitted transplacentally during pregnancy or possibly by contact to maternal lesions at birth . It has been estimated that up to 80% of children exposed to Treponema pallidum do indeed develop CS.
Consequences for the unborn or infant presumably depend on the time of infection of the mother. Early, intrauterine infection may not even be symptomatic at birth, but can also lead to preterm birth, hydrops fetalis or still birth.
According to estimations published by the World Health Organization (WHO), annually about 2,000,000 pregnant women get infected with Treponema pallidum . Considering the aforementioned number of up to 80% of exposed fetuses becoming infected, one would estimate 1,600,000 children to be born with CS.
CS is a major public health problem in developing countries, particular in sub-Saharan Africa and subtropical Asia. Some studies report augmented case numbers in the Western world. Prenatal screenings and treatment of affected mothers would be desirable, may, however, not be available in all developing countries.
The spirochete bacterium Treponema pallidum is the causative agent of CS. Particularly women with primary and to a lesser degree those with secondary syphilis are at high risk to transmit the disease to their unborn children. Transmission is possible at all times during gestation. Children generally show symptoms of CS during the first two years of their life, only in rare cases do symptoms manifest later, a condition which is termed late CS . Prenatal infection with Treponema pallidum can provoke neonatal death and stillbirth or may lead to severe disabilities such as neurologic problems, deafness and bone deformities . Even though embryonal organogenesis is usually unaffected by infections with Treponema pallidum, CS is accompanied with systemic complications similar to those observed in secondary stage adult syphilis. All organ systems may thus be affected by CS.
Contrary to classical CS that develops in children aged under two years, late CS is not considered contagious.
Routine testing of pregnant mothers and, in case of positive results, consecutive treatment against Treponema pallidum often cures mother and child. The WHO does recommend such screenings to be part of the routine examinations done in the first and last trimester of pregnancy . Only in a few cases that are not diagnosed and treated until late pregnancy children may still show symptoms of CS at birth.
At birth, another routine screen should be carried out. Children at risk of infection should be monitored closely. In order to identify those children at risk, improved surveillance and follow-up data would be desirable .
Serologic monitoring is particularly important for mothers with a medical history of syphilis. Increases in antibody titers may indicate a possible relapse and thus prompt treatment. Reinfections are also possible.
Since syphilis is a contagious infectious disease, family members of the patient should be tested clinically and serologically for signs of infection. It may be the case that the patient diagnosed with syphilis is not the pregnant woman herself but someone she had sexual intercourse with. The probability that the woman did acquire syphilis is about 25 to 50%. Thus, she should be treated.
Of note, medical personnel or other people in close contact with patients suffering from early CS may get infected. They should be examined for possible lesions two to three weeks afterwards and serologically screened at this point in time as well as three months later. They should be treated if necessary. After close, unprotected contact with the affected child before he or she was diagnosed with CS, even immediate treatment may be indicated.
Congenital syphilis (CS) results from intrauterine infection with Treponema pallidum, causative agent of syphilis. Mothers suffering from stage one or two syphilis do very likely transmit the infection to their unborn child. This may result in neonatal death, stillbirth. If a living child is born, he or she may show some signs of CS, but infants usually develop first symptoms some weeks after birth. Late CS is a rare variant of CS and affects children older than two years . Symptoms comprise skin and mucosal lesions, hematological alterations and hepatomegaly, bone lesions and CNS symptoms.
Routine screens during pregnancy allow identification of infected mothers. Penicillin treatment is effective and generally cures mother and child. Despite those preventive measures, CS continues to concern health care providers and case numbers are increasing in developing and even in some developed countries  .
Children are at risk of developing congenital syphilis (CS) if their mother is infected with Treponema pallidum, causative agent of syphilis. She may transmit the disease to her unborn child if she is not or only inadequately treated. Increasing case numbers of CS have been observed in some industrialized countries, presumably due to lessening awareness among future parents.
The disease may lead to stillbirth, life-threatening illness or severe disability in affected children. In order to prevent these consequences, routine screens should be performed during early and late pregnancy and at delivery. An effective treatment is available and consists in the application of antibiotics.