Why does syphilis spread to the brain and nerves?

Treponema pallidum invades the central nervous system within weeks of initial acquisition in many people. In most cases, the immune system clears the organisms. In others — particularly when syphilis goes untreated — bacteria persist and cause progressive inflammation of the brain, spinal cord, blood vessels, eyes, and ears. Early invasion causes meningitis or stroke; late invasion decades later can cause dementia, psychiatric change, or loss of balance and sensation (tabes dorsalis). HIV co-infection accelerates progression and lowers the threshold for symptomatic disease, with roughly 20–30% of neurosyphilis cases occurring in people with HIV.

Does everyone with syphilis need a lumbar puncture?

No — a lumbar puncture is not routine for all syphilis. It is indicated when there is any neurological symptom (cognitive change, weakness, sensory loss, cranial nerve palsy), any visual symptom (uveitis, blurred vision, optic neuritis), any auditory symptom (sudden hearing loss, tinnitus, vertigo), suspected tertiary syphilis, or treatment failure when blood test titres do not decline fourfold by 12–24 months. Importantly, ocular and ear involvement is always treated as neurosyphilis even if the lumbar puncture result is normal — the clinical picture overrides the CSF result in these cases.

How is neurosyphilis treated and how long does it take?

The standard Australian treatment is benzylpenicillin 1.8 g (3 million units) given intravenously every four hours for 10–14 days. Most Australians receive this via Hospital in the Home (HITH), where a nurse visits daily to administer the infusion. A hospital admission is needed for the first dose so doctors can monitor for reactions. Intramuscular penicillin (Bicillin/benzathine benzylpenicillin) does not reach adequate concentrations in the brain or spinal fluid and cannot be used for neurosyphilis — this is a critical prescribing point. Follow-up blood tests check treatment response at 3, 6, 12, and 24 months.

What symptoms improve with treatment — and what might remain?

Early neurosyphilis — meningitis, meningovascular stroke — often responds well to treatment, with partial or full neurological recovery possible. Late parenchymatous disease — dementia from general paresis, or sensory ataxia from tabes dorsalis — can stabilise with treatment, but structural neuronal damage that has already occurred is unlikely to fully reverse. This is why early recognition matters significantly. Ocular and auditory involvement sometimes improves with prompt IV benzylpenicillin, though outcomes depend on the severity and duration before treatment. Blood test titres (RPR/VDRL) are monitored at intervals to confirm the infection is responding to treatment.

Do I need to notify my sexual partners?

Yes — partner notification is mandatory for syphilis in Australia. Anyone who has had sexual contact with you in the relevant lookback period (typically 3 months for early syphilis, up to 2 years for late) should be tested and treated if needed. Your GP or a sexual health clinic can assist. Let Them Know (letthemknow.org.au) is a free Australian service allowing anonymous partner notification by SMS or email without revealing your name. Syphilis is also a notifiable disease — your GP is legally required to report the diagnosis to the state or territory Public Health Unit within prescribed timeframes.

What is the Jarisch-Herxheimer reaction and is it dangerous?

The Jarisch-Herxheimer reaction is an inflammatory response to bacterial die-off that occurs within 2–24 hours of the first penicillin dose. Symptoms include fever, rigors, headache, and muscle aches. It is not an allergic reaction to penicillin and is usually self-limiting within 24 hours, managed with paracetamol and oral fluids. In pregnancy, the reaction can trigger uterine contractions, which is why pregnant people with syphilis are hospitalised for their first dose. Clinicians can distinguish a Herxheimer reaction from a true allergy by the timing and the specific pattern of symptoms involved.

Neurosyphilis

Neurosyphilis: CNS syphilis recognition and management in AU general practice

By Dr HB Lo, FACRRM Reviewed 13 October 2026 13 min read

Neurosyphilis — CNS invasion by Treponema pallidum — can occur at any syphilis stage, from early meningitis or stroke to late dementia and sensory ataxia decades after the original infection. Australia declared syphilis a Communicable Disease Incident of National Significance in August 2024.

Any neurological, ocular, or auditory symptom in a patient with known or suspected syphilis requires lumbar puncture and treatment as neurosyphilis.

Treatment is benzylpenicillin 1.8 g IV every four hours for 10–14 days, usually delivered via Hospital in the Home. Syphilis is notifiable in every Australian jurisdiction and partner notification is mandatory.

What neurosyphilis actually is

Syphilis — caused by the bacterium Treponema pallidum — has undergone a dramatic resurgence in Australia. The Australian Centre for Disease Control (CDC Australia) recorded 5,866 notifications in 2024, double the number from a decade earlier. In August 2024, Australia’s Chief Medical Officer declared syphilis a Communicable Disease Incident of National Significance — among the country’s highest public health alert levels — driven by congenital cases, 34 infant deaths over 10 years, and rates among Aboriginal and Torres Strait Islander people running approximately seven times those of non-Indigenous Australians.

Neurosyphilis is the invasion of the central nervous system (CNS) by T. pallidum. It is not a historical curiosity: with rising rates, more patients are progressing to late or complicated disease without adequate treatment. Neurosyphilis can emerge at any stage of untreated infection — not only decades later. For general practitioners, the critical skill is recognition: any neurological, ocular, or auditory symptom in a patient with known or suspected syphilis must trigger investigation, regardless of how subtle or psychiatric the presentation appears.

This article follows the Australian STI Management Guidelines — Syphilis and Therapeutic Guidelines (eTG) — Antibiotic as primary references, with international guidelines providing supplementary evidence where the AU sources are silent.

A. Core clinical — the AU general-practice framework

Classification — what type of neurosyphilis?

Early neurosyphilis (months to a few years post-infection):

Asymptomatic neurosyphilis — CSF abnormalities (pleocytosis, raised protein, reactive CSF-VDRL) without clinical symptoms; identified incidentally on lumbar puncture done for another indication
Syphilitic meningitis — headache, photophobia, meningism, cranial nerve palsies, particularly CN II (optic), VII (facial), and VIII (auditory/vestibular)
Meningovascular neurosyphilis — inflammatory endarteritis of CNS blood vessels causing ischaemic stroke, typically involving the middle cerebral artery territory in a younger person 5–10 years after infection

Late neurosyphilis (parenchymatous — decades post-infection):

General paresis — progressive frontal lobe and hippocampal neuronal loss causing personality change, grandiose or paranoid delusions, behavioural disinhibition, dementia, dysarthria, and tremor; untreated, it progresses to total dementia and death
Tabes dorsalis — degeneration of dorsal columns and dorsal roots causing sensory ataxia (positive Romberg sign), areflexia in the lower limbs, Charcot joints (painless destructive arthropathy of the knee or ankle), lightning pains, urinary retention, impotence, and the Argyll Robertson pupil
Gummatous neurosyphilis — rare granulomatous CNS mass lesions that can mimic primary brain tumour on imaging

Ocular and otosyphilis are treated as neurosyphilis regardless of CSF findings, per Australian STI Management Guidelines and CDC STD Treatment Guidelines 2021. Uveitis, optic neuritis, retinitis, sudden sensorineural hearing loss, and persistent vertigo in a patient with syphilis all require IV benzylpenicillin, not intramuscular benzathine penicillin.

History to take

A focused history should cover:

Sexual history — five Ps (partners, practices, protection, past STIs, pregnancy plans); prior syphilis diagnoses, treatment dates, regimens, and post-treatment titre follow-up
Neurological symptoms — headache, neck stiffness, photophobia; stroke-like episodes (focal limb weakness, dysarthria, hemianopia), particularly in a person under 50; personality or behavioural change; cognitive decline; irritability or disinhibition not explained by a prior psychiatric history
Psychiatric features — grandiose or paranoid delusions, new-onset mania or psychosis, major depression without prior history
Visual symptoms — blur, floaters, painful eye movement, colour desaturation
Auditory symptoms — sudden or progressive hearing loss, tinnitus, true vertigo
Sensory symptoms — lightning pains in the legs, urinary incontinence, impotence, broad-based unsteady gait
HIV status and risk — co-infection is present in 20–30% of neurosyphilis cases and alters diagnostic thresholds and management
Pregnancy status in women of reproductive age — congenital syphilis risk
Prior treatment adequacy — date, regimen, and titre response; inadequately treated early syphilis increases late-stage risk
Aboriginal or Torres Strait Islander background — given the ongoing remote-area outbreak across WA, NT, QLD, and SA since 2017

Examination

Physical findings to look for:

Argyll Robertson pupil — small (1–2 mm), irregular pupils that constrict to near vision but do not react to direct light; pathognomonic of late neurosyphilis when bilateral
Cranial nerve assessment — visual acuity, fundoscopy for papillitis, chorioretinitis, or optic atrophy (CN II); facial asymmetry (CN VII); and hearing (CN VIII)
Tabes dorsalis features — positive Romberg sign, absent lower-limb deep tendon reflexes, impaired vibration and proprioception in feet, broad-based gait, Charcot joints (painless, destructive arthropathy most often at knee or ankle)
Cognitive screen — Montreal Cognitive Assessment (MoCA) or RUDAS for Aboriginal and Torres Strait Islander patients
General paresis features — perioral and tongue tremor, dysarthria, frontal release signs (grasp reflex, palmomental reflex), hyperreflexia
Secondary syphilis stigmata that may indicate active systemic disease — maculopapular rash (classically palms and soles), condylomata lata, mucous patches

B. Diagnosis: serology, lumbar puncture, and imaging

Serology

The Australian STI Management Guidelines recommend a treponemal-first reflex pathway:

Treponemal test (TP-EIA / CMIA / TPPA / TPHA) as first-line AU screen — positive in both active and previously treated syphilis; once reactive, usually remains so for life and is not a measure of disease activity
Non-treponemal test (RPR or VDRL with titre) — quantitative marker of disease activity; serial titres guide treatment response and detect reinfection (rising titre = reinfection rather than treatment failure)

MBS item 69384 covers syphilis serology and is bulk-billable. HIV serology (4th-generation Ag/Ab combined assay) must be performed concurrently in every patient with syphilis — co-infection is present in 20–30% of neurosyphilis cases and influences management thresholds.

Lumbar puncture — when to perform

Lumbar puncture (LP) is indicated when there is:

Any neurological symptom (cognitive change, weakness, sensory loss, cranial nerve palsy, stroke-like episode)
Any visual symptom (uveitis, optic neuritis, sudden visual loss, retinitis) — note ocular syphilis is treated as neurosyphilis even if LP is normal
Any auditory symptom (sudden sensorineural hearing loss, persistent tinnitus, vertigo) — same principle
Suspected tertiary syphilis (cardiovascular gummata)
Treatment failure — RPR titre does not decline fourfold (two dilutions) by 12–24 months despite stage-appropriate treatment

CSF findings supportive of neurosyphilis per Australian STI Management Guidelines:

CSF VDRL reactive — highly specific but only 30–70% sensitive; a reactive result with no blood contamination confirms the diagnosis
CSF FTA-ABS — high negative predictive value; useful to exclude neurosyphilis if negative
CSF white cell count >5/mm³ (lymphocytic predominance); use >20/mm³ threshold in HIV co-infected to account for baseline HIV-related pleocytosis
CSF protein >40 mg/dL

Imaging

MRI brain (MBS 63007 GP-referred under restricted indications; 63551 specialist-referred) is preferred over CT:

Meningovascular neurosyphilis: small-vessel infarcts, periventricular T2 signal changes
General paresis: cerebral atrophy, particularly frontal and temporal lobes
Gumma: ring-enhancing mass with surrounding oedema, may be indistinguishable from tumour without the syphilis serological context

CT brain (MBS 56001 without contrast) is appropriate when MRI is unavailable or contraindicated.

C. Treatment: benzylpenicillin and the HITH pathway

First-line treatment

Per Australian STI Management Guidelines and eTG — Antibiotic:

Benzylpenicillin 1.8 g (3 million units) IV every 4 hours for 10–14 days (total 10.8–16.2 g/day) — equivalent to the international standard of aqueous crystalline penicillin G 18–24 million units per day.

Most Australians receive this via Hospital in the Home (HITH) after an initial supervised inpatient dose. HITH uses an elastomeric pump for continuous or intermittent infusion administered by a nurse; it is funded under state and territory programs (not MBS — bundled hospital activity). Eligibility requires clinical stability, an adequate home environment, and reliable daily nurse access. Refer via the local hospital’s HITH service.

Penicillin allergy

Desensitisation in a monitored inpatient setting is strongly preferred over alternatives — particularly in pregnancy, where benzylpenicillin is the only agent reliably effective for fetal CNS protection (Australian STI Management Guidelines; CDC STD 2021)
Ceftriaxone 2 g IV or IM daily for 10–14 days — used only if desensitisation is impossible; safe only in delayed (non-IgE-mediated) penicillin reactions; approximately 10% cross-reactivity risk in IgE-mediated allergy; retrospective multicentre evidence supports comparability in treatment response (Bettuzzi et al., Lancet Infect Dis 2021)
Doxycycline 200 mg orally twice daily for 28 days — very limited evidence for CNS penetration; last-line only when IV access is impossible and ceftriaxone is contraindicated; not safe in pregnancy; specialist input is mandatory before use

Jarisch-Herxheimer reaction and critical prescribing alert

Jarisch-Herxheimer reaction: warn every patient receiving their first dose of benzylpenicillin. The reaction occurs within 2–24 hours of treatment initiation — fever, myalgia, rigors, tachycardia, and transient hypotension from inflammatory cytokine release as T. pallidum lyses. It is not a drug allergy. Management is supportive (paracetamol, oral or IV fluids) and it typically resolves within 24 hours. In pregnancy, the reaction can precipitate preterm labour — hospitalise the patient for the first dose.

Critical prescribing alert: benzathine benzylpenicillin (Bicillin L-A) — used for primary, secondary, and early-latent syphilis — does not achieve treponemicidal concentrations in the CSF and must not be used for neurosyphilis. A national Bicillin L-A shortage affecting TGA supply through at least November 2026 (TGA s19A Extencilline supply active) further increases risk of under-treatment for upstream syphilis stages — reinforcing the importance of detecting neurosyphilis early.

Follow-up

Post-treatment monitoring uses serial RPR/VDRL titres at 3, 6, 12, and 24 months. Successful treatment is defined as a fourfold (two-dilution) decline in titre by 12–24 months. Repeat LP is required only if titres fail to decline appropriately or if symptoms recur. A serofast state — stable low-titre RPR without fourfold decline — is a recognised entity in late syphilis and is not treatment failure; specialist input assists interpretation.

D. Australian operations

Notification and contact tracing

Syphilis is notifiable in every Australian jurisdiction. GPs must notify the relevant state or territory Public Health Unit (PHU) within prescribed timeframes — typically within 5 days for standard notifications; congenital syphilis requires same-day urgent notification. Notification is separate from, and in addition to, partner notification.

Partner notification is mandatory for syphilis. Let Them Know provides a free, confidential Australian online service allowing patients to notify sexual contacts anonymously by SMS or email, without disclosing their identity. Lookback periods vary by stage: 3 months for early syphilis, up to 2 years for late latent or tertiary. For complex contact tracing — particularly in Aboriginal and Torres Strait Islander outbreak regions — engage the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) or the relevant Aboriginal Community Controlled Health Service (ACCHS) and state outbreak coordinator per the National Syphilis Response Plan 2023–2030.

MBS items

Key items for neurosyphilis management:

Syphilis serology MBS 69384 — treponemal plus non-treponemal; bulk-billable
Standard GP consult items 3 / 23 / 36 / 44 for the consultation itself
MRI brain 63007 (GP-referred, restricted indications) / 63551 (specialist-referred)
CT brain 56001 (without contrast) / 56007 (with contrast)
Chronic disease management plan items 965 / 967 — for late neurosyphilis with persistent cognitive or mobility sequelae qualifying as a chronic condition
Mental Health Care Plan 2700 / 2701 — for psychiatric presentations, adjustment disorder, or psychosocial burden of the diagnosis
Telehealth video 92029 / phone 92060 — appropriate for titre follow-up review with an established patient (12-month existing-relationship rule applies)
715 Aboriginal and Torres Strait Islander Health Assessment 715 (updated 1 March 2026 per NACCHO) — particularly valuable given the ongoing remote outbreak; claimable once per 9 months
ATSI follow-up items 10987 / 10997 — up to 10 services per year for post-715 outreach STI re-screening and treatment completion

Medico-legal

Driving: persistent cognitive impairment, visual field loss, or severe sensory ataxia from late neurosyphilis may create an obligation to notify the state driver licensing authority. Advise patients to discuss driving safety with their specialist; document this discussion.

Fitness for work and NDIS: late neurosyphilis with significant neurological disability may qualify for NDIS support in selected cases. My Aged Care applies for older patients requiring community care secondary to neurological sequelae.

E. Special populations

HIV co-infection

HIV co-infection is present in approximately 20–30% of neurosyphilis cases. HIV accelerates syphilis progression, lowers the threshold for symptomatic neurosyphilis, produces more atypical presentations, and increases the relapse rate post-treatment. Diagnostic adjustments: use CSF WCC >20/mm³ (rather than >5) to diagnose neurosyphilis in HIV-positive patients to account for baseline HIV-related pleocytosis. Ensure antiretroviral therapy (ART) is initiated or optimised concurrently — PBS Section 100; refer to an HIV physician or the local sexual health service. Check CD4 count and HIV viral load as part of the baseline workup.

Pregnancy

Congenital syphilis has caused 34 infant deaths over the past decade in Australia. Pregnant people with neurosyphilis must receive benzylpenicillin IV — no alternative agent reliably crosses the placenta to protect the foetus. Penicillin allergy in pregnancy mandates in-hospital desensitisation, not substitution with ceftriaxone or doxycycline. The Jarisch-Herxheimer reaction can precipitate preterm labour — hospitalise the patient for the first dose and involve the obstetric team. Notify the neonatal unit and PHU immediately; congenital syphilis notification is a separate urgent event requiring multidisciplinary coordination.

Aboriginal and Torres Strait Islander people

Rates run approximately seven times those of non-Indigenous Australians. The ongoing remote-area outbreak across WA, NT, QLD, and SA since 2017 is driven by heterosexual transmission, structural health access gaps, and inadequate sexual health workforce coverage. Culturally safe, trauma-informed practice is non-negotiable. Engage the relevant ACCHS and state outbreak coordinator per the National Syphilis Response Plan 2023–2030. Use the 715 health assessment and ATSI follow-up items for structured outreach re-screening and treatment completion. RACGP and ACRRM competency frameworks for rural generalist practice emphasise syphilis screening in high-prevalence remote communities.

Older adults

Late neurosyphilis — general paresis and tabes dorsalis — affected older pre-antibiotic cohorts and occasionally presents in people over 60 with a long-undiagnosed infection. Unexplained cognitive decline with personality change, progressive sensory ataxia, or Charcot joint development in an older patient without clear vascular risk factors warrants syphilis serology, particularly in the context of a sexual history suggesting historical risk. The RUDAS cognitive screen is validated for use in culturally and linguistically diverse older adults and Aboriginal and Torres Strait Islander populations.

When to escalate

Refer urgently to the emergency department or admitting specialist when:

Any suspected neurosyphilis — IV penicillin requires admission for first-dose monitoring and HITH setup
Acute meningovascular stroke presentation — neurology and infectious diseases
Ocular syphilis with any vision-threatening symptom — same-day ophthalmology referral
Sudden sensorineural hearing loss — urgent ENT and audiology
Pregnant patient with syphilis and any neurological symptom — obstetrics + infectious diseases + PHU
Penicillin allergy requiring in-hospital desensitisation before treatment can begin

Refer urgently (within 48–72 hours) to a sexual health physician or infectious diseases specialist for:

Treatment planning and HITH coordination
Complex partner notification and contact tracing
HIV co-infection management and ART initiation
Diagnostic uncertainty — distinguishing serofast state from treatment failure, or assessing whether LP is indicated

What to send with the referral: complete serology with dates and titres, prior treatment history with regimens, HIV status and CD4/viral load, full neurological and examination findings, imaging results and CSF if performed, partner contact information, and pregnancy status.

What this article is and is not

This article is a clinical education resource for general practice clinicians and patients, written to Australian primary-tier guidelines. It is not personalised medical advice. Clinical decisions about investigation, treatment, and notification require assessment by a registered medical practitioner with access to the individual patient’s complete history, examination, and current clinical condition.

Information is reviewed to the standard of publicly available Australian sources and may not reflect local institutional protocols or very recent guideline updates. It does not constitute an endorsement of any specific product, service, or treatment provider.

If you are concerned about syphilis or a neurological symptom, please see your general practitioner or attend a sexual health clinic. HealthDirect provides a GP and nurse helpline (1800 022 222) for Australians unsure where to seek care.

Sources cited

Australian STI Management Guidelines — Syphilis. ASHM.
Therapeutic Guidelines Limited. eTG complete — Antibiotic: syphilis.
Australian Centre for Disease Control — Syphilis; CDNA SoNG v2.0 September 2024.
National Syphilis Response Plan 2023–2030. Australian Government.
Melbourne Sexual Health Centre — Syphilis Treatment Guidelines.
CDC STD Treatment Guidelines 2021 — Syphilis. US CDC.
ASHM — Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine.
TGA — medicinal product alerts. Benzathine benzylpenicillin shortage s19A notice.
MBS Online — items 69384, 63007, 63551, 56001, 56007, 965, 967, 2700, 2701, 715, 10987, 10997, 92029, 92060, 3, 23, 36, 44.
NACCHO — MBS 1 March 2026 updates. 715 holistic restructure.
HealthDirect — Syphilis. Australian Government.
Better Health Channel — Syphilis. Victorian Government.
Let Them Know — partner notification service.
Marra CM et al. Pilot study evaluating ceftriaxone and penicillin G as treatment agents for neurosyphilis in HIV-infected individuals. Clin Infect Dis 2000;30:540–544.
Bettuzzi T et al. Ceftriaxone compared with benzylpenicillin in the treatment of neurosyphilis in France. Lancet Infect Dis 2021.
Luetkemeyer AF et al. Postexposure doxycycline to prevent bacterial sexually transmitted infections. N Engl J Med 2023;388:1296–1306.

Frequently asked questions

Why does syphilis spread to the brain and nerves?

Treponema pallidum invades the central nervous system within weeks of initial acquisition in many people. In most cases, the immune system clears the organisms. In others — particularly when syphilis goes untreated — bacteria persist and cause progressive inflammation of the brain, spinal cord, blood vessels, eyes, and ears. Early invasion causes meningitis or stroke; late invasion decades later can cause dementia, psychiatric change, or loss of balance and sensation (tabes dorsalis). HIV co-infection accelerates progression and lowers the threshold for symptomatic disease, with roughly 20–30% of neurosyphilis cases occurring in people with HIV.
Does everyone with syphilis need a lumbar puncture?

No — a lumbar puncture is not routine for all syphilis. It is indicated when there is any neurological symptom (cognitive change, weakness, sensory loss, cranial nerve palsy), any visual symptom (uveitis, blurred vision, optic neuritis), any auditory symptom (sudden hearing loss, tinnitus, vertigo), suspected tertiary syphilis, or treatment failure when blood test titres do not decline fourfold by 12–24 months. Importantly, ocular and ear involvement is always treated as neurosyphilis even if the lumbar puncture result is normal — the clinical picture overrides the CSF result in these cases.
How is neurosyphilis treated and how long does it take?

The standard Australian treatment is benzylpenicillin 1.8 g (3 million units) given intravenously every four hours for 10–14 days. Most Australians receive this via Hospital in the Home (HITH), where a nurse visits daily to administer the infusion. A hospital admission is needed for the first dose so doctors can monitor for reactions. Intramuscular penicillin (Bicillin/benzathine benzylpenicillin) does not reach adequate concentrations in the brain or spinal fluid and cannot be used for neurosyphilis — this is a critical prescribing point. Follow-up blood tests check treatment response at 3, 6, 12, and 24 months.
What symptoms improve with treatment — and what might remain?

Early neurosyphilis — meningitis, meningovascular stroke — often responds well to treatment, with partial or full neurological recovery possible. Late parenchymatous disease — dementia from general paresis, or sensory ataxia from tabes dorsalis — can stabilise with treatment, but structural neuronal damage that has already occurred is unlikely to fully reverse. This is why early recognition matters significantly. Ocular and auditory involvement sometimes improves with prompt IV benzylpenicillin, though outcomes depend on the severity and duration before treatment. Blood test titres (RPR/VDRL) are monitored at intervals to confirm the infection is responding to treatment.
Do I need to notify my sexual partners?

Yes — partner notification is mandatory for syphilis in Australia. Anyone who has had sexual contact with you in the relevant lookback period (typically 3 months for early syphilis, up to 2 years for late) should be tested and treated if needed. Your GP or a sexual health clinic can assist. Let Them Know (letthemknow.org.au) is a free Australian service allowing anonymous partner notification by SMS or email without revealing your name. Syphilis is also a notifiable disease — your GP is legally required to report the diagnosis to the state or territory Public Health Unit within prescribed timeframes.
What is the Jarisch-Herxheimer reaction and is it dangerous?

The Jarisch-Herxheimer reaction is an inflammatory response to bacterial die-off that occurs within 2–24 hours of the first penicillin dose. Symptoms include fever, rigors, headache, and muscle aches. It is not an allergic reaction to penicillin and is usually self-limiting within 24 hours, managed with paracetamol and oral fluids. In pregnancy, the reaction can trigger uterine contractions, which is why pregnant people with syphilis are hospitalised for their first dose. Clinicians can distinguish a Herxheimer reaction from a true allergy by the timing and the specific pattern of symptoms involved.

Source quality

Sources grouped by evidence tier. AU primary tier first; international where AU is silent or lagging; named-author reconstruction where guidelines have not yet caught up. How tiers work.