Summary

Syphilis is a sexually transmitted infection (STI) caused by the spirochaete bacterium Treponema pallidum. Known as "The Great Imitator" for its protean manifestations, syphilis progresses through distinct stages: Primary (Chancre), Secondary (Systemic rash, lymphadenopathy), Latent (Asymptomatic), and Tertiary (Gummas, Cardiovascular, Neurosyphilis). Transmission is via sexual contact (genital, anal, oral) or vertical (congenital). Incidence is rising globally. Diagnosis is by Serology (Treponemal tests: EIA, TPPA; Non-Treponemal tests: RPR/VDRL for activity/monitoring). Treatment is with Penicillin – simple and highly effective. Benzathine Penicillin G IM is first-line for most stages; IV Benzylpenicillin is required for neurosyphilis. The Jarisch-Herxheimer reaction (Fever, rigors after first dose) can occur and patients should be warned. Partner notification and HIV testing are essential. [1,2]

Clinical Pearls

"The Great Imitator": Syphilis can mimic almost any disease. Always consider it in unexplained rashes, neurological syndromes, or aortic pathology.

Painless Chancre (Primary): The ulcer is classically painless, clean-based, with indurated edges. Heals spontaneously in weeks, but infection persists.

Rash on Palms and Soles (Secondary): This is a classic exam clue. Most rashes spare palms/soles – Syphilis and RMSF don't.

Argyll Robertson Pupil = Neurosyphilis: Pupils accommodate but do not react to light ("Prostitute's Pupil" – Accommodates but doesn't react).

Primary Syphilis (3-90 days post-exposure)

Secondary Syphilis (4-10 weeks after Chancre)

Latent Syphilis

Tertiary Syphilis (Years to Decades Later – Rare Now)

Neurosyphilis

Can occur at any stage (Early or Late).

Congenital Syphilis

• Excellent with Treatment: Penicillin is highly effective. Most stages curable.
• Neurosyphilis: Arrested with treatment, but some deficits may be irreversible.
• Untreated: 30% develop Tertiary disease.

Key Guidelines

What is Syphilis?

Syphilis is a sexually transmitted infection caused by a type of bacteria. It develops in stages and can be easily treated with antibiotics if caught early. If left untreated for many years, it can cause serious problems with the heart and brain.

How is it spread?

Through sexual contact (vaginal, anal, or oral sex). It can also be passed from mother to baby during pregnancy.

What are the symptoms?

• Stage 1: A painless sore (ulcer) on the genitals, anus, or mouth that heals on its own.
• Stage 2: A rash (often on palms and soles), flu-like symptoms, swollen glands.
• Later Stages: Often no symptoms (hidden), but can cause heart and brain problems years later if untreated.

How is it treated?

With Penicillin injections. It is very effective. You may feel unwell for a day after the first injection (a normal reaction). Your sexual partners also need to be tested and treated.

Common Exam Questions

1. Classic Lesion of Primary Syphilis: "Describe the Chancre."
   • Answer: Single, Painless ulcer with Clean base and Indurated (Hard) edges. At site of inoculation. Heals spontaneously.
2. Rash Distribution in Secondary Syphilis: "Where is the rash typically located?"
   • Answer: Generalised Maculopapular rash involving Palms and Soles.
3. Argyll Robertson Pupil: "What is it pathognomonic of?"
   • Answer: Neurosyphilis. Pupils Accommodate but do Not React to light.
4. Treatment of Primary Syphilis: "First-line treatment?"
   • Answer: Benzathine Penicillin G 2.4 MU IM Single Dose.

Viva Points

• Jarisch-Herxheimer: Explain the reaction and warn patients.
• RPR/VDRL Monitoring: 4-fold decline expected with successful treatment.

Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.