Syphilis

Syphilis is an STD which is sometimes called lues. It’s caused by infection of the spirochete Treponema pallidum. It’s a very rare disease nowadays. Mostly only the primary stage is seen nowadays.

Risk factors

• Men who have sex with men
• Promiscuity
• Unprotected sex

Clinical features

Incubation period can last from 10 – 90 days (average 21). Syphilis has 4 characteristic stages

• Primary syphilis
  • Characterised by a special lesion called a chancre
  • Chancres occur at the site where the bacterium enters the body
  • It’s a painless, firm ulcer with indurated borders and a smooth base
  • Chancres resolve spontaneously without scarring after 3 – 6 weeks
• Secondary syphilis
  • Known as the “great imitator” as its skin symptoms resemble those of many other skin diseases
  • Begins 8 – 12 weeks after primary infection
  • Lasts 2 – 6 weeks
  • Condyloma lata
    • Broad-based, wart-like papular erosions
    • In anogenital region, intertriginous folds, oral mucosa
  • Disseminated, polymorphic, symmetric rash
  • Mucous patches (White patches on mucous membranes)
  • Patchy alopecia
  • Necklace of Venus = hypopigmentation around the neck
• Latent syphilis
  • The patient is seropositive but there are no symptoms
  • Can last months, years or the rest of the patient’s life
  • There are four outcomes:
    • The disease resolves and the patient becomes healthy
    • The disease reactivates as secondary syphilis
    • The disease progresses into tertiary syphilis
    • The patient dies before any of these outcomes occur
• Tertiary syphilis
  • Occur in approx. 30% of untreated patients in the latent stage
  • Gummas (Destructive and ulcerative granulomatous lesions with necrotic centre)
    • Can occur anywhere on or in the body, even on organs and bones
  • Nodules
  • Psoriasiform granulomatous lesions
  • Cardiovascular syphilis
    • Aortitis with resulting aneurysm of the aorta
    • Dilated aortic root
  • Neurosyphilis
    • Meningitis
    • Stroke
    • Tabes dorsalis (broad-based sensory ataxia)
    • Dysesthesia
    • General paresis
    • Widespread cerebellar atrophy
    • Dementia
    • Argyll Robertson pupil (Bilateral miosis, pupils don’t react to light)

Diagnosis and evaluation

A specimen is taken from a lesion. Nontreponemal tests like RPR and VDRL are used for screening. These are sensitive but not specific tests. Treponemal tests are used for confirming the diagnosis. These are highly specific.

Direct visualization of treponema is also possible, and may be useful in the primary stage, when the serological tests below can be negative. The bacteria are visible by darkfield microscopy.

Treatment

• For prevention, primary, secondary, and early latent syphilis: 2,4 million units of benzathine penicillin G intramuscularly – single dose (one 1,2 mill IU vial in each gluteus)
• For tertiary (except neurosyphilis) and late latent syphilis: 2,4 million units of benzathine penicillin G IM – once weekly for three weeks
• For neurosyphilis: IV penicillin G for 10 to 14 days

Jarisch-Herxheimer reaction may occur after treatment is initiated. It's a systemic reaction to bacterial endotoxins. It is usually self-limiting.