Congenital syphilis

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See syphilis for epidemiology. Cases among young fertile women increasing, so likely to be more cases in future. Worldwide, 1 million pregnancies per year affected, of which 50% result in fetal death, and the other 50% in congenital infection (although most asymptomatic at birth).

Contents

Clinically

Two thirds of infected babies are asymptomatic at birth. Otherwise:

  • Rhinitis with "snuffles" (vesicles on upper lip, highly infectious)
  • Lymphadenopathy
  • hepatosplenomegaly
  • hepatitis
  • anaemia
  • hydrops
  • meningitis
  • pneumonia

Later:

  • Typical facies including frontal bossing, saddle nose, short maxilla, high palate
  • Mulberry Molar (5 blobs in ring shape to tooth, pathognomic!), Hutchinson's incisors (peg-like) better known.
  • Gummata (rubbery ulcers)
  • Sabre tibia (anterior bowing)
  • Hutchinson’s triad = interstitial keratitis, peg shaped incisors, and 8th nerve deafness.

High risk infants

  • Signs of congenital syphilis
  • High maternal antibody titres eg VDRL > 1:16
  • Inadequate course of maternal treatment as defined below
  • Mothers with symptoms of primary syphilis shortly before delivery (irrespective of the VDRL result).

Investigations

See syphilis#Investigations for testing in pregnancy or mothers postnatally.

  • Direct dark field microscopy of mucous patches, snuffles or placenta. Beware non treponemal spirochaetes are seen in the mouth.
  • Blood tests: VDRL, FTA IgM. Neonatal VDRL 4x higher than maternal is highly suggestive of infection.
  • Lumbar puncture if high risk, looking for cell count, protein, VDRL.
  • Chest X-ray - fluffy infiltrates (pneumonia alba)
  • X-ray of long bones (periostitis, osteitits, and osteochondritis)
  • Ophthalmology assessment

Treatment

High risk or symptomatic babies should be treated with benzylpen 100-150 000 U/kg/d in bd or tds doses (concern about CSF levels with benzathine penicillin) for 10-14/7. Late diagnosis >4/52 give 200-300 000 U/kg/d qds for 10-14/7.


Prevention

For early acquired disease in pregnancy (primary, secondary or latent of <1yr), single dose benzathine penicillin 50 000U/kg (but exclude neurological involvement). For syphilis >1yr duration give 3 doses at weekly intervals. For neurological involvement, give benzylpenicillin 50 000U/kg qds for 10-14/7 followed by 3 doses benzathine penicillin as above.

Adequate antenatal treatment is defined as:

  1. adequate benzathinepenicillin dose (2.4M Units IM once weekly x3 - erythromycin is not reliable)
  2. at least 30 days before birth
  3. proven 4x drop in nontreponemal serology.

Follow up

Follow up for high risk infants is essential at 3, 6, 9, 12 months or until VDRL is unrecordable, to ensure adequate treatment. If the VDRL is not falling or is increasing then repeat treatment with the above course is necessary. Those infants in whom CSF was indicative of neurosyphilis will require repeat examination of CSF. If CSF VDRL is not negative after six months then a further course of treatment is indicated and a repeat CSF should be tested in a further 6 months.

Low risk babies should be followed up to check VDRL is falling.

Late Disease

ie over 2 yrs of age. X-ray changes seen in 20% of asymptomatic especially ankles, knees but also wrists, elbows. Lesions are destructive, symmetric, multiple.