Syphilis

Sometimes called lues
Treponema pallidum
Risk factors
- Men who have sex with men
- Promiscuity
- Unprotected sex
Incubation period 10 – 90 days (average 21)
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
  - Both systemic and mucocutaneous lesions
  - Begins 8 – 12 weeks after primary infection
  - Lasts 2 – 6 weeks
  - Disseminated, symmetric rash
    - Polymorphic, i.e. can take on many appearances
    - Typically nonpruritic macular or papular rash
    - Reddish-brown
    - Roseola syphilitica = macules on trunk and flexor aspects of the extremities
    - Corona veneris
      - Maculopapular lesions
      - On forehead or back of neck
    - Clavus syphiliticus = maculopapular lesions on palms and soles
  - Mucous patches
    - White patches on mucous membranes
  - Condyloma lata
    - Broad-based, wart-like papular erosions
    - In anogenital region, intertriginous folds, oral mucosa
  - Patchy alopecia
  - Leucoderma syphiliticum
    - Hypopigmentation
    - Necklace of Venus = hypopigmentation around the neck
    - Differential diagnosis: pityriasis versicolor
  - Non-cutaneous and non-mucosal symptoms
    - Pharyngitis
    - Iritis
    - Hepatitis
    - Generalized nontender lymphadenopathy
    - Meningitis
- 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
  - Late benign syphilis
    - 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
    - Early neurosyphilis
      - Meningitis
      - Stroke
    - Late neurosyphilis
      - Tabes dorsalis
        Demyelination of the dorsal column and dorsal root ganglia
        
        Causes a broad-based ataxia
      - Dysesthesia
      - General paresis
      - Widespread cerebellar atrophy
      - Dementia
      - Argyll Robertson pupil (Bilateral miosis, pupils don’t react to light)
- Diagnosis
  - Direct visualization of treponema
    - In the primary stage, when the serological tests below can be negative
    - Darkfield microscopy
    - Specimen from a lesion
  - Nontreponemal tests – for screening
    - RPR
    - VDRL
    - Sensitive, not specific
  - Treponemal test – for confirming the diagnosis
    - TPPA
    - FTA-ABS
    - Specific, not sensitive
- Treatment
  - For prevention, primary, secondary and early latent syphilis
    - 2,4 million units of benzathine penicillin G intramuscularly – single dose
  - 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
    - Systemic reaction to bacterial endotoxins
    - Is usually self-limiting
  - In case of penicillin allergy
    - Doxycycline
    - Desensitization to penicillin, then use penicillin as normal