Congenital Syphilis

Authors:

Ankita Taneja, MD
Resident Physician, Department of Pediatrics, University of Florida College of Medicine, Jacksonville, Florida

Kartikeya Makker, MD
Assistant Professor, Department of Pediatrics, University of Florida College of Medicine, Jacksonville, Florida

Carlos A. Arango, MD
Assistant Professor, Department of Pediatrics, University of Florida College of Medicine, Jacksonville, Florida

Citation:

Taneja A, Makker K, Arango CA. Congenital syphilis [published online January 23, 2018]. Consultant for Pediatricians.

A full-term neonate was born to a 21-year-old mother who had had inadequate prenatal care. The child had been born at 38 weeks via an uneventful but precipitous spontaneous vaginal delivery 1 hour after rupture of membranes and with meconium-stained amniotic fluid. The neonate was vigorous and received routine neonatal resuscitation care. The Apgar score was 9 at 1 minute and 9 at 5 minutes.

Physical examination. Physical examination findings at birth were normal. The neonate’s weight was appropriate for gestational age. In the first 12 hours of life, the neonate showed signs of hypothermia (lowest temperature, 36.1°C), tachypnea (70-85 breaths/min, with no work of breathing), hypotonia of both upper limbs, a high-pitched cry, and increased irritability and tenderness even upon gentle handling of the upper extremities.

Neurologic examination revealed weak palmar grasp, delayed and incomplete Moro reflex bilaterally, and an inability to elicit active wrist extension bilaterally. Generalized activity and lower limb tone and reflexes were normal. There was no shoulder dystocia, birth trauma, or difficult extraction.

Diagnostic tests. Chest radiographs revealed minimal interstitial fluid in the lung fields and no clavicular fractures.

Results of maternal blood tests for HIV, hepatitis B virus, and group B streptococcus (GBS) were negative. Results of urine drug screens were positive for oxycodone in the mother but negative in the neonate.

Results of maternal rapid plasma reagin (RPR) testing were reactive for syphilis at a 1:32 titer. The mother had had nonreactive RPR test results approximately 13 months before delivery, and she was unaware of any positive RPR test results in the more distant past. A maternal Treponema pallidum particle agglutination (TPPA) assay was performed to confirm the positive RPR results; TPPA results were pending at the time of initial workup of the neonate.

A sepsis screen, including a complete blood cell count (CBC) and blood cultures, as well as liver function tests (LFTs), a hepatitis C antibody test, and an RPR test, were performed on the neonate. A neonatal lumbar puncture was performed to determine blood cell count and levels of protein and glucose in the cerebrospinal fluid (CSF); a VDRL test, Gram staining, and cultures also were performed on the CSF.

CBC results were positive for leukocytosis (15,000 white blood cells/μL; reference range, 4500-11,000/μL), a reduced hemoglobin level of 12.6 g/dL (reference range, 14.0-17.5 g/dL), a low hematocrit of 38.6% (reference range, 41%-50%), and a low platelet count 133 × 10³/μL (reference range, 150-350 × 10³/μL) with 48% neutrophils, 8% bands, 30% lymphocytes, 11% monocytes, and 3% eosinophils. Neonatal blood cultures were negative for pathogens.

LFT results included the following values: total protein, 5.4 g/dL (reference range, 6.5-8.3 g/dl); albumin, reduced at 3.0 g/dL (reference range, 3.5-5.0 g/dL); aspartate aminotransferase, elevated at 45 U/L (reference range, 10-30 U/L); alanine aminotransferase, normal at 18 U/L (reference range, 10-40 U/L); total bilirubin, elevated at 3.1 mg/dL (reference range, 0.3-1.2 mg/dL); direct bilirubin, elevated at 2.7 mg/dL (reference range, 0.1-0.3 mg/dL), and alkaline phosphatase, elevated at 255 U/L (reference range, 30-120 U/L).

The neonate’s RPR test results were reactive for syphilis at a 1:16 titer, and CSF VDRL test results were reactive at 1:1 titer. Neonatal fluorescent treponemal antibody-absorption test results also returned positive. Maternal TPPA results had also returned positive by the neonate’s third day of life, thus confirming the diagnosis of untreated maternal syphilis and congenital neonatal neurosyphilis with bilateral upper-extremity weakness likely secondary to syphilitic pseudo paralysis or palsy.

Treatment. Crystalline penicillin was given for neonatal syphilis in addition to ampicillin and gentamicin for neonatal sepsis.

Further workup of the neonate included an ophthalmologic assessment and long-bone radiographs at 1 week of life. Radiographs showed a serrated appearance bilaterally at the femoral distal metaphyses with faint lucent metaphyseal bands, likely indicating syphilitic changes (Figures 1 and 2). Long-bone radiographs of both upper limbs had normal findings (Figures 3 and 4). Results of the ophthalmologic assessment were normal.

Figure 1. Radiograph showing syphilitic changes in the patient's right femur.

Figure 2. Radiograph showing syphilitic changes in the patient's left femur.

Figure 3. Radiograph showing normal findings in the patient's right upper extremity.

Figure 4. Radiograph showing normal findings in the patient's left upper extremity.

After the initial symptoms, the neonate had no further problems and did well overall during the hospital stay while being treated for congenital neurosyphilis. Crystalline penicillin was continued for a total of 10 days. Ampicillin and gentamicin were discontinued at 48 hours of life. The neonate also received physical therapy for the limb hypotonia and limitation of movement. Postdischarge follow-up with pediatric infectious disease specialists and physical therapists was arranged.

Differential diagnosis. Neonatal sepsis is a common condition that could have explained the neonate’s initial hypothermia and tachypnea. The chest radiographs revealed only minimal interstitial fluid, and the tachypnea resolved by 24 hours of life, suggesting transient tachypnea of the newborn as a possible diagnosis.

An appropriately thorough initial workup included blood cultures and the initiation of broad-spectrum antibiotics to cover common bacterial pathogens. Inadequate prenatal care, unknown maternal GBS status at birth, and the neonate’s clinical presentation made a diagnosis of bacterial sepsis a likely possibility. However, the negative blood culture results and the positive RPR results ruled out this diagnosis.

A diagnosis of brachial palsy also was considered in light of the hypotonia in the neonate’s upper extremities. The lack of shoulder dystocia and trauma during delivery made this an unlikely possibility. However, the child’s precipitous delivery plus the fact that brachial palsy can occur even without trauma at birth made this diagnosis possible. Once the diagnosis had been made evident by positive RPR results, the upper-limb hypotonia was likely explained by pseudoparalysis, which is commonly reported in cases of congenital syphilis.

Discussion. Vertical transmission of syphilis was first demonstrated almost a century ago.¹

T pallidum, the causative agent of syphilis, is a motile spirochete. Infants can become infected via transplacental transmission from an infected mother during any stage of pregnancy.² Approximate rates of transmission are 60% to 100% for primary and secondary syphilis and 10% to 40% for latent syphilis.¹ Congenital syphilis is a largely preventable illness.³

Syphilis is estimated to affect 1 million pregnancies annually worldwide.³ The prevalence of congenital syphilis is increasing in the United States and Europe.^3-5 Its incidence had declined to a historic low in 2000.¹ However, between 2005 and 2008, rates of congenital syphilis and primary and secondary syphilis rose by 38% in the US and many European Countries.¹

Congenital syphilis is defined as early and late disease based on the appearance of clinical signs before or after age 2 years. Early congenital syphilis typically presents at 4 to 8 weeks of age. It is most commonly asymptomatic, but symptoms may include persistent rhinitis, pneumonia, osteochondritis, rash, pseudo paralysis, anemia, thrombocytopenia, and hepatomegaly with or without splenomegaly. Skeletal changes are most commonly present on long bones.¹

Late congenital syphilis presents after age 2 years, is a result of chronic inflammation, and predominantly affects the central nervous system (CNS), bones, and teeth. Neurosyphilis and eight cranial nerve involvement characterize CNS findings. Hutchinson teeth (peg-shaped incisors), deafness, and interstitial keratitis form the 3 components of the Hutchinson triad that is pathognomonic for congenital syphilis. Saddle nose, frontal bossing, saber shin, and Clutton joints are some of the classical skeletal findings.¹

Clinical takeaway. Congenital syphilis in the era of universal screening is preventable and should be rare. However, congenital syphilis outbreaks recently have been reported in the United States,⁵ and in many other parts of the world. This case highlights an important clinical aspect of early congenital syphilis in neonates and serves as a reminder that it is a continuing concern.

References:

1. Kwak J, Lamprecht C. A review of the guidelines for the evaluation and treatment of congenital syphilis. Pediatr Ann. 2015; 44(5):e108-e114.
2. Woods CR. Syphilis in children: congenital and acquired. Semin Pediatr Infect Dis. 2005; 16 (4):245-257.
3. Walker DG, Walker GJ. Forgotten but not gone: the continuing scourge of congenital syphilis. Lancet Infect Dis. 2002; 2(7):432-436.
4. Karp G, Schlaeffer F. Syphilis and HIV co-infection. European Journal of Internal Medicine 20 (2009) 9-13
5. Bowen V, Su J, Torrone E, et al. MMRW. Increase in Incidence of Congenital Syphilis- United States, 2012-2014. Nov 13, 2015/64 (44), 1241-1245.