Green Teeth? The Many Shades of Congenital Syphilis

by Darsi Perusini, BSc, DDS, MSc, FRCD(C); Heather Dreise, MD, FRCPC

It is a disease that you will learn about in dental school, but rarely see in actual practice. And given the many, varied features of congenital syphilis, when you do encounter your first case, you may need to review this condition and its presentation.

Syphilis, generally, is on the rise in Canada. Between 2005 and 2014, there were 49 reported cases of congenital syphilis in Canada;1 in 2018, 10 times more syphilis infections were recorded in Alberta than in 2014, and the proportion of women infected rose from 5% to 39%, resulting in more infants being diagnosed with the congenital variety.2 Vertical transmission from mother to unborn child can occur anytime between nine weeks gestation and birth. Typically, 70-100% of untreated primary or secondary syphilis, 40% of early latent syphilis and 10% of late latent syphilis result in transmission to the unborn child.1

With a steady increase in cases over the years, it is imperative that dentists understand congenital syphilis, its presentation and how it is managed.

Case Report
A 14-month-old male presented to a pediatric dental office following a referral from his pediatrician. The toddler’s foster mother was concerned about the child’s “green teeth”. The foster mother did not report any issues with feeding or other behaviour that would suggest the boy was in pain.

The toddler’s medical history was significant for hyperbilirubinemia, neonatal seizures and global developmental delay, all associated with congenital syphilis. He had a milk protein allergy, and was currently taking ferrous sulfate, levetiracetam, ursodiol and vitamin D.

On clinical examination, the toddler had no significant extra-oral findings. His dental examination revealed an incomplete primary dentition. Teeth 81 and 82 appeared to be fused. Green intrinsic discoloration was noted on all the erupted teeth, along with moderate to severe enamel dysplasia. Fig. 1

Fig. 1

 Intra-oral photograph of toddler
Intra-oral photograph of toddler

Arrested decay was evident on the maxillary incisors. Radiographic examination showed normal trabecular bone pattern and maxillary incisors with enamel hypoplasia and open apices. Fig. 2
The working diagnoses were intrinsic discoloration secondary to neonatal liver disease, generalized enamel dysplasia, fused teeth 81 and 82, and early childhood caries. Restorative treatment was not indicated at the time due to the boy’s fragile medical condition, and the arrested nature of the decay. The importance of good oral hygiene and dietary habits was reviewed with the foster mother. Fluoride varnish was applied to the boy’s teeth, and he was booked for follow up in three months’ time.

Fig. 2

Maxillary periapical radiograph of toddler
Maxillary periapical radiograph of toddler

Discussion
Congenital syphilis has a range of presentation throughout the lifespan. (Fig. 3)3,4,5 Prior to delivery, it can manifest as spontaneous abortion, still birth and hydrops fetalis. At birth, one may see necrotizing funisitis,6 a pathogneumonic change to the umbilical cord that is indicative of congenital syphilis. Infants can have rhinitis or snuffles, with thick bloody discharge from their nose – and short stature may be noted for the gestational age. Roughly 40-50% of affected children will present with neurosyphilis.

Fig. 3

 Congenital syphilis throughout the lifespan.
Congenital syphilis throughout the lifespan.

A typical presenting sign for babies within the first two months of life is rashes on the palms and soles of the feet. These are maculopapular rashes that can result in desquamation, vesicular, bullous, papulosquamous or mucosal lesions. Several weeks after their initial appearance, these rashes can fade to a subtle copper color.

For infants suffering from congenital syphilis, the first two months of life can also see the emergence of hepatosplenomegaly, which can persist for years or be associated with hepatic dysfunction. Musculoskeletal involvement is characterized by long bone abnormalities, increasing the risk of fractures. Bony changes are typically bilateral.

Hematologic abnormalities, such as anemia and thrombocytopenia, can occur, and infants may require transfusions to manage these abnormalities.

After two years of life, signs of late congenital syphilis include frontal bossing, saddle nose deformity, short maxilla and a protuberant mandible. Children may also develop paroxysmal cold hemaglobinuria. Once children start school, neurologic changes may become evident through intellectual or learning disabilities.

During puberty, further complications can occur. Eyes can develop interstitial keratitis that may progress to secondary glaucoma, corneal scaring and optic atrophy. Sensorineural hearing loss can also develop due to osteochondritis of the otic capsule and cochlear degeneration. Teenagers may experience rhagades, which are cracks or fissures around the mouth. As growth velocity increases, saber shins (anterior bowing of the shins) and Clutton’s joints (painless arthritis of the knees) can develop.

Regardless of when congenital syphilis manifests, its management requires a team approach. The first step is obstetric, focusing on prevention through testing, treating and following syphilis in pregnancy. Timely evaluation and management of infants with congenital syphilis is critical: infants should be closely monitored and treated with the guidance of pediatric infectious disease. Finally, children with congenital syphilis must be followed by community pediatricians who can facilitate access to specialty care according to how the disease manifests.

Dental Implications
There are a number of features associated with congenital syphilis that dentists may see in their practice. In the presented case, the boy arrived with a confirmed diagnosis of congenital syphilis, which is often how dentists will first meet these children. Universal screening of all pregnant women for syphilis is the standard of care in most jurisdictions across Canada, meaning that the condition is typically identified before children are born7.

The classic dental manifestations of congenital syphilis are Hutchinson’s incisors and mulberry molars.8 Fig. 4 The disorder usually affects the permanent central incisors and mandibular first molars. The combination of teeth defects, deafness and interstitial keratitis is referred to as Hutchinson’s triad.

Hutchinson’s incisors appear notched at the incisal edge, and are wider in the mesial/distal dimension at the cervical third of the tooth compared to the incisal third. (Fig. 4A) The affected incisors are often broadly spaced and are shorter than adjacent teeth. Mulberry molars are thicker at the gingival margin than the occlusal table, and have many small cusps. (Fig. 4B) The enamel is often hypoplastic.

Fig. 4

Classic dental manifestations of congenital syphilis. 4A. Hutchinson’s incisors. 4B. Mulberry molar.
Classic dental manifestations of congenital syphilis.
4A. Hutchinson’s incisors. 4B. Mulberry molar.

This particular case depicts green staining of the primary dentition as a result of hepatic dysfunction. Tooth discoloration can be divided into one of two categories: extrinsic and intrinsic. Extrinsic staining occurs when pigment deposits on the surface of the tooth (e.g. coffee or nicotine staining). Intrinsic staining occurs when pigment is incorporated into the dentine or enamel (e.g., tetracycline or hyperbilirubinemia staining). When bilirubin levels are elevated for several months, the pigment can deposit in the teeth. Intrinsic staining of primary teeth secondary to hyperbilirubinemia may vary in colour from yellow to dark green.

Conclusion
More cases of children with congenital syphilis are appearing across Canada. These children can experience a gamut of comorbidities, including issues with dental development. It is important for dentists to appreciate the condition, along with its presentation and overall management, to facilitate care as part of a multidisciplinary team.

Oral Health welcomes this original article.

References

  1. Robinson, J. L. (2018). Congenital syphilis. No longer just of historical interest. Canadian Paediatric Society. https://www.cps.ca/documents/position/congenital-syphilis.
  2. Alberta Health, Government of Alberta. (2018). Alberta sexually transmitted infections and HIV 2018. https://open.alberta.ca/publications/9781460145449.
  3. Dobson, S. (2020). Congenital syphilis: Clinical features and diagnosis. UpToDate. https://www.uptodate.com/contents/congenital-syphilis-clinical-features-and-diagnosis/print
  4. Centers for Disease Control and Prevention. (2015). Congenital syphilis. https://www.cdc.gov/std/tg2015/congenital.htm
  5. Arnold, S. R., & Ford-Jones, E. L. (2000). Congenital syphilis: A guide to diagnosis and management. Paediatric Child Health, 5(8): 463-69.
  6. Fojaco, R. M., Hensley, G. T., & Moskowitz, L. (1989). Congenital syphilis and necrotizing funisitis. Journal of the American Medical Association, 261(12): 1788-90.
  7. Public Health Agency of Canada, Government of Canada. (2007). Congenital syphilis face sheet. https://www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/congenital-syphilis-fact-sheet.html
  8. Budnick, S. D. (1981). Handbook of pediatric oral pathology. Year Book Medical Publishers, Inc.

About the Author

Darsi Perusini is a pediatric dentist in Edmonton, Alberta, and is a part-time clinical instructor and lecturer in the Department of Pediatric Dentistry at the University of Alberta. Darsi would like to thank Dr. Drew Czernick and Natika Culham (natikadesign.com) for their assistance with the preparation of this article.

Heather Dreise is a community pediatrician practicing in rural Alberta with a special interest in indigenous health, and is a clinical lecturer in the Department of Pediatrics at the University of Alberta.

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