Syphilis: Stages, Symptoms, Testing, and Treatment

Syphilis is the infection most likely to fool you. The primary sore is painless and often in a location where it goes unnoticed. The rash looks like dozens of other conditions. The latent phase has no symptoms at all. By the time tertiary syphilis produces cardiovascular or neurological damage, years have passed and the opportunity for simple treatment is long gone. Every stage of syphilis is treatable with penicillin — the difference is that early treatment is a single injection, while late-stage disease requires hospitalisation.

Quick answer: Syphilis progresses through four stages: primary (painless sore), secondary (rash, flu-like illness), latent (no symptoms, still present), and tertiary (organ damage). A blood test (RPR) detects it. Penicillin G cures it at every stage. Same-day testing is available in Atlanta, San Antonio, Miami, Chicago, and Denver.

Primary Syphilis: The Chancre

The first sign of syphilis is a chancre — a firm, painless sore at the site of entry, typically appearing 3 weeks after exposure (range: 10–90 days). Chancres appear on the genitals, anus, lips, or anywhere with direct contact. Because the sore is painless, it is frequently missed — particularly when inside the vagina, on the cervix, or inside the anal canal. The chancre heals on its own within 3–6 weeks, creating the most dangerous misconception in STD medicine: many people assume the problem resolved. It did not. The bacteria have entered the bloodstream.

Secondary Syphilis: The Rash

Secondary syphilis develops 4–10 weeks after the chancre. The characteristic rash involves the palms and soles — this is unusual for most common skin conditions and is a key clinical clue. The rash doesn't itch. Systemic symptoms include fever, fatigue, swollen lymph nodes, sore throat, and patchy hair loss. Secondary symptoms resolve spontaneously, again reinforcing the false impression that infection has cleared. This is the most infectious stage.

Latent Syphilis: Silent Persistence

Latent syphilis is the period of no symptoms but persistent infection, confirmed only by blood test. Early latent (within the first year) and late latent (more than a year or unknown duration) are distinguished because early latent patients can still have infectious relapses. Pregnant women with late latent syphilis can still transmit to the fetus. Latent syphilis is commonly discovered incidentally during prenatal screening, STD panels, or blood donation.

Tertiary Syphilis

Approximately one-third of untreated people progress to tertiary syphilis after 10–30 years. The three major manifestations are gummatous disease (granulomatous lesions on skin, bone, or organs), cardiovascular syphilis (aortitis causing aneurysm and valve incompetence), and neurosyphilis (meningitis, stroke, dementia, blindness, hearing loss). Neurosyphilis can occur at any stage — any person with syphilis and neurological or visual symptoms needs cerebrospinal fluid evaluation regardless of stage.

Testing

The standard approach uses two tests. A non-treponemal test (RPR or VDRL) detects antibodies produced in response to tissue damage and quantifies titer levels — titers fall with treatment and rise with reinfection. A treponemal test (TPPA, FTA-ABS, or EIA) detects antibodies specific to Treponema pallidum and remains positive for life regardless of treatment. A reactive RPR is confirmed with a treponemal test. RPR titers are followed over time: a four-fold fall indicates adequate treatment; stable or rising titers suggest failure or reinfection. The window period for syphilis testing is 3–6 weeks after exposure.

Treatment

Penicillin G is the only reliably effective treatment at all stages. For primary, secondary, and early latent syphilis: a single intramuscular injection of benzathine penicillin G 2.4 million units. For late latent or unknown duration: three weekly injections. For neurosyphilis: intravenous aqueous crystalline penicillin G for 10–14 days. For penicillin-allergic non-pregnant adults: doxycycline 100mg twice daily for 14 days (early) or 28 days (late latent). Pregnant women with penicillin allergy should be desensitised — no alternative is proven safe in pregnancy. A Jarisch-Herxheimer reaction (fever and worsening of symptoms within 24 hours) occurs in many early-stage patients, resolves in 24 hours, and is not a reason to stop treatment.

When to Seek Urgent Care

• Neurological or visual symptoms with known syphilis: same-day evaluation — possible neurosyphilis requiring lumbar puncture and IV treatment.

• Syphilis diagnosis during pregnancy: contact your OB the same day. Treatment timing directly affects fetal outcomes.

• Partner disclosure of syphilis: test within 1–2 weeks and discuss empirical treatment with your provider.

Frequently Asked Questions

Can syphilis be cured completely?

Yes, at every stage. Early treatment prevents all long-term complications. Late-stage treatment stops progression but cannot reverse existing organ damage — which is exactly why early detection and treatment matter.

How do I know if I have syphilis with no symptoms?

You don't, without testing. A blood test (RPR) is the only way to detect latent syphilis. This is why annual testing for sexually active people with multiple partners, and screening during all pregnancies, are essential.

Can I get syphilis from oral sex?

Yes. Syphilis transmits through direct contact with a chancre or secondary lesion, which can be on the lips, mouth, or throat. Oral sex with an infected partner can transmit syphilis, including to the throat.

Is syphilis contagious after treatment?

No. Effective treatment eliminates infectiousness. Abstain from sex until treatment is complete and any sores have healed. Partners from the previous 90 days (primary), 6 months (secondary), or 1 year (early latent) should be tested and treated.

Related: STDs in Pregnancy · STI Epidemic 2025 · Can You Have an STD With No Symptoms? · Get tested today →