Syphilis

Question 1

Aetiology of syphilis

Answer 1

spirochete bacterium Treponema pallidum
Incubation around 21 days
Transmission:
- Sexually, direct contact with an infectious lesion
- Vertically from mother to child
- Sharing of needles
- Blood products or organ transplant

Question 1

Risk factors for syphilis

Answer 1

Unprotected sex
Multiple or anonymous sexual partners
Substance use (including alcohol and illicit drugs) before sex
Transactional sex (commercial sex work, exchange of sex for drugs)
Previous or current diagnosis of any sexually transmitted infection
Social vulnerability e.g. poverty, homelessness, migrant, refugee status
Needle-sharing contact with a known syphilis case
Serosorting among MSM living with HIV (choosing a partner based on perceived HIV status)
Risk compensation related to pre-exposure prophylaxis for HIV

Question 2

Symptoms of syphilis

Answer 2

Genital warts: Usually a single painless wart, but may be painful
Non-pruritic rash on the palms and soles
Moist warts at the sites of skin friction e.g. perianal, vulval, breasts, axillae
Lesions on the inside of the mouth
Constitutional: fever, malaise, fatigue, arthralgia
Lumps (lymphadenopathy)
Neurological symptoms (seizure, hearing loss, headache and meningism, peripheral neuropathy)
Ophthalmological symptoms (visual impairment, eye pain)
Rhinitis (sign of congenital syphilis)

Question 3

What are the stages of syphilis

Answer 3

1. Primary (resolves in 3-8w):
   - painless ulcer (chancre) at the site of infection (most commonly genital area)
   - local lymphadenopathy
2. Secondary (Systemic involvement, resolves in 2-12w):
   - Skin and hair changes such as a maculopapular rash, condyloma lata (Moist wart-like lesions) and patchy alopecia
   - Oral lesions (snail tract lesions)
   - Generalised lymphadenopathy
   - Low-grade fever, headache, and malaise
3. Late (defined as more than 2 years after infection):
   - Late latent syphilis - confirmed infection in the absence of any current clinical features
   - Tertiary syphilis - rare, but may present with cardiac disease e.g. aortic aneurysm, cutaneous disease e.g. gummatous lesions, and/or neurological disease

Question 4

What are the signs of syphilis on examination

Answer 4

General exam (scalp, mouth, palms, soles)
- Symmetrical, non-pruritic maculopapular rash (palms of the hands and soles of the feet)
- Moist wart-like lesions (condylomata lata) — usually develop at sites of skin friction such as perianal and vulval regions, under the breasts, and axillae.
- Patchy lesions on the oral mucosa (‘snail tract’ lesions).
- Regional (primary) or generalised (secondary) lymphadenopathy (moderately enlarged, rubbery)
Genital exam
- Genital lesion(s) - solitary, painless, indurated, genital ulcer (chancre) with a clean base and sharp border.
- Regional lymphadenopathy
Neuro: ?neurosyphilis
Eye: optic neuropathy, uveitis, retinitis
Cardio: murmurs (aortic regurgitation), signs of HF

Question 5

What are the features of neurosyphilis

Answer 5

Areflexia
Meningitis.
Cranial nerve palsies (in particular II and VIII).
Hearing loss.
Tabes dorsalis (inflammation of spinal dorsal column/nerve roots) — may present with ‘lightening pains’, paraesthesia, Charcot’s joints, pupillary change (Argyll-Robertson pupils), absent reflexes, joint position and vibration sense.
General paresis (cortical neuronal loss) — may present with forgetfulness and personality change which develop into severe dementia
Seizure
Peripheral neuropathies

Question 6

What investigations should be done for syphilis

Answer 6

1. Refer to a genito-urinary medicine (GUM) specialist for laboratory investigations (such as dark-field microscopy and serology) and a full sexual health screen (including HIV testing).

Bedside: Swabs from active lesions for dark-field microscopy or PCR → Coiled spirochaete bacterium with a corkscrew appearance and motility

Bloods:
- rapid plasmin reagin (RPR) (non-treponemal, requires specific test follow up)
- venereal disease research laboratory test (VDRL) (non-treponemal, requires specific test follow up)
- Treponemal enzyme immunoassay (EIA) or treponemal chemiluminescent assay (CLIA)
- Treponema pallidum haemagglutination/particle assay (TPHA/TPPA)
- Fluorescent treponemal antibody absorption test (FTA-abs)

Other
- LP: ? neurosyphilis
- CXR: ?aortic regurg, HF
- Echo: ?aortic regurg, HF

Question 7

What is the management for syphilis

Answer 7

1. Refer to GUM specialist
2. Advise the person to avoid all sexual contact and exposure of other people to active lesions until the diagnosis is excluded, or successful treatment of the condition has been confirmed.
3. Abx:
   - Early infection: Benzathine benzylpenicillin IM single dose
   - Late infection: Benzathine benzylpenicillin IM x3
   - (Alternative doxycycline if PenAll)
4. Consider corticosteroid therapy (3 days PO pred)
5. Repeat bloods 3/12 (4 fold drop in RPR)

Question 8

What is the management for neurosyphilis

Answer 8

1. IV aqueous benzylpenicillin 4 hourly, 14/7
2. IM procaine benzylpenicillin + oral probenecid
3. Consider corticosteroids (prednisolone)

Question 9

What are the complications of syphilis

Answer 9

Neurosyphilis → meningitis, hearing loss, uveitis, keratitis, memory/cognition decline, seizures, ataxia, Charcot’s joints
Cardio: aortic aneurysm, aortic regurgitation, HF
Gummatous: necrotic centred lesions
Psychological and social complications
Congenital syphilis
HIV infection

Treatment: jarisch-herxheimer reaction

Question 10

What is the prognosis for syphilis

Answer 10

Syphilis can be cured if treated with appropriate antibiotics before complications develop
Untreated, around 1/3 of cases progress to later stages of disease, resulting in severe, sometimes irreversible, CVD, neurological and ocular complications
Treatment in late syphilis usually halts infection, but some Treponema spirochetes can persist in protected sites like the eye and CNS