This podcast covers congenital syphilis, including epidemiology, pathophysiology, impacts on mothers and infants, prenatal screening, bloodwork and follow-up for infants exposed in utero. This podcast was developed by Stephanie Unrau, a third year medical student at the University of Alberta with Dr. Joan Robinson, a pediatric infectious disease specialist at the Stollery Children’s hospital in Edmonton, Alberta.
What follows is from the script:
Syphilis is caused by a type of bacteria called a spirochete, and more specifically, the treponema pallidum spirochete. It is transmitted by contact with certain skin lesions on a sexual partner that are teeming with spirochetes. These skin lesions include chancres, mucous patches, and large, raised, grey-white lesions on moist skin called condylomata lata. They will occur
on whatever body part came into contact with the partner’s skin lesion. Chancres are the most common form of syphilitic skin lesion, and are usually small and painless so infected
people often do not know that they have them. As one might predict, chancres are often in the genital region, allowing transmission to a partner during oral, vaginal, or anal sex.
Syphilis can be transmitted to the fetus in-utero if it is in maternal blood, or very rarely from lesions in the birth canal.
As mentioned before, syphilis infection has five stages known as primary, secondary, early latent, late latent and tertiary syphilis.
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Back to the script:
Think of primary syphilis as the local replication of spirochetes at the site where skin or a mucous membrane has made contact with a partner’s infectious lesion. Within 10 to 90 days, the spirochetes typically form a single painless chancre at the site of contact. The infected individual will probably not notice the chancre and will feel well but be very infectious. Chancres disappear without treatment due to the immune response. However, this allows the spirochetes to enter the bloodstream, and four to ten weeks later the host will develop Secondary Syphilis.
Think of secondary syphilis as a diffuse spirochete infection causing immune complex deposition that manifests as a multitude of symptoms. This phase lasts 2-6 weeks and
almost always includes skin and mucous membrane involvement.
The classic skin manifestation of secondary syphilis is a diffuse maculo-papular rash involving the palms and soles. In fact, whenever you see a rash on the palms or soles of a patient, you should consider the possibility of syphilis. Additionally, the skin manifestations seen in primary syphilis can recur as well. There can be alopecia. Because the bacteria is in the blood, the patient commonly has constitutional symptoms, like low grade fever, malaise, anorexia, weight loss, head ache, and painless and generalized lymphadenopathy. Less commonly there are end-organ infections including meningitis, nephritis, hepatitis, and uveitis. Despite these possible manifestations, the majority of the time secondary syphilis is not diagnosed as the patient is not very sick so does not seek medical advice or clinicians mistakenly think that the patient has a viral illness.
The symptoms of secondary syphilis usually resolve without treatment. However, up to one year after the initial infection, the spirochetes can go back into the blood and cause secondary syphilis manifestations again. This can happen once, several times, or not at all in the first year after initial infection. This stage is known as early latent syphilis. If still untreated, the patient then progresses to late latent syphilis.
The patient with late latent syphilis will be clinically well and no longer infectious. Spirochetes are still present in the body but are no longer in the blood, so the patient will have no symptoms. However, slow, granulomatous inflammation around a smaller number of spirochetes in the body continues and after five to forty years, the patient may develop tertiary syphilis.
Tertiary syphilis is the fifth and final stage of syphilis and presents with potentially fatal or debilitating sequelae, such as neurosyphilis, cardiovascular syphilis, and gumma deposition. Neurosyphilis5 is a term which includes general paresis and dementia, tabes dorsalis meaning sensory ataxia, meningovascular syphilis meaning stroke, retinitis, and
meningitis. Cardiovascular syphilis refers to aortitis and associated sequelae. Gummas can deposit on and affect skin, bones, and organs. Although only one third of patients develop
tertiary syphilis, it is likely that all patients with latent syphilis would develop it given enough time, but they pass away from other causes first.
Once the clinician suspects syphilis based on history and/or clinical presentation, they must test for it. They should always preform serology. This entails treponemal and
nontreponemal tests and will be explained later in greater detail. In addition, if there is a skin lesion, the clinician should perform a direct swab of it for molecular testing with nucleic acid amplification testing (NAAT)2.
The only treatment considered to definitively treat syphilis is penicillin, and the number of doses depends on the stage2,6 Therefore, in the case of penicillin allergy, desensitization therapy followed by penicillin treatment is recommended, and is considered the only definitive treatment for syphilis in pregnancy6
Now that we’ve got an overview of syphilis out of the way, let’s focus on congenital syphilis. The majority of infants diagnosed with early congenital syphilis are asymptomatic at birth. Nonetheless, it is imperative to recognize and treat congenital syphilis as soon as possible to prevent lifelong sequelae. We will organize the symptoms and sequelae by a systems approach1:
– Spontaneous abortion, stillbirth, or hydrops fetalis (which is extreme edema of the fetus) occur in approximately 40% of cases where syphilis is acquired DURING pregnancy. Necrotizing funisitis7 is a rare finding pathognomic to congenital syphilis involving infection and inflammation of the soft tissue of the
umbilical cord. The umbilical cord in this situation looks like a “barber shop pole.”
– A classic finding of congenital syphilis is a rash that begins as small, erythematous, maculopapular spots that are most prominent on the back, buttocks, posterior thighs, and plantar surfaces of the feet8. This rash typically appears 1-2 weeks after birth8. Less commonly, infectious lesions full of treponemes like those found on adults can also be found on infants8.
– The CNS manifestation of neurosyphilis can be present at birth, or have a delayed presentation8. Infants with neurosyphilis can be asymptomatic. On the other hand, they can present like bacterial meningitis, with vomiting, bulging
fontanelle, and increased head circumference8. Chronic meningovascular syphilis presents with progressive hydrocephalus, cranial nerve palsies, neurodevelopmental regression, and seizures8. Cerebral infarction can be caused by syphilitic endarteritis as early as the second year of life!8
– There are many eye, ear, nose, and mouth signs and symptoms of congenital syphilis1,8. Rhinitis and snuffles are often the first symptoms of congenital syphilis, and especially in conjunction with rash and hepatosplenomegaly should make you think of congenital syphilis. Dental changes that may be apparent when the teeth erupt include mulberry molars with extra cusps on them. The front teeth may have notches on them and these are called Hutchinson’s teeth. Hearing loss can occur due to involvement of the eighth cranial nerve. Eye and vision can be affected by interstitial keratitis, meaning corneal scarring. Facial features can be altered on a skeletal level, including frontal bossing, poorly developed maxillas, and a collapsed or saddle nose.
– Infection of bones and cartilage leads to painful osteochondritis or perichondritis1,8. Shortly after birth, the infant is reluctant to move the limb
because it hurts, making it appear like they have paralysis. If not treated, after 2 years of age they may suffer from recurrent arthropathies as well as painless knee effusions, called Colleton’s joints. Years later they can develop winged scapulas and sabre shins.
– Hematological issues may include anemia and thrombocytopenia1.
– GI changes may include hepatosplenomegaly1. To emphasize a take home point that was said above, the combination of hepatosplenomegaly, snuffles, and rash
in an infant should always make you suspect and investigate for congenital syphilis.
Review how Alberta screens prenatally for syphilis9: