syphilis

Question 1

diagnosis of syphilis

Answer 1

darkfield microscopy of exudates from lesions

2 serological tests

Question 2

primary syphilis

Answer 2

heals spontaneously in 1-8w
external genitalia, perianal region, mouth, throat
single painless ulcer or chancre at site of infection, may also present with multiple atypical or painful lesions

Question 3

secondary syphilis

Answer 3

develops 2-8w after initial infection in untreated or inadequately treated individual; disappears in 4-10w if untreated
multisystem involvement due to hematogenous and lymphatic spread
can include skin rash, mucocutaneous lesions and lymphadenopathy

Question 4

latent syphilis

Answer 4

early latent < 1y
late latent > 1y
develops 4-10w after secondary state in untreated or inadequately treated individual
possible multisystem involvement
asymptomatic but picked up by serology testing; internal organs continue to be affected by infection

Question 5

tertiary syphilis

Answer 5

develops in approx 30% of untreated/inadequately treated individuals 10-30y after initial infection
possible multisystem
can present with gummatous lesions in joints leading to impaired movement; cardiac involvement leading to heart-aortic insufficiency

Question 6

neurosyphilis

Answer 6

CNS involvement in any stage
cognitive dysfunction, motor or sensory deficits, ophthalmic or auditory symptoms, signs and symptoms of meningitis, stroke, etc

Question 7

treponemal test

Answer 7

TPHA, TPPA
uses treponemal antigen to detect treponemal antibody
sensitive and specific, used as confirmatory tests
not used for monitoring

Question 7

non-treponemal test

Answer 7

VDRL, RPR test
uses cardiolipin to detect treponemal antibodies
most dilute serum concentration with positive reaction reported
antibody titres correlate with disease activity, used as tool to monitor response to treatment

Question 8

Primary, secondary or early latent syphilis treatment

Answer 8

Benzathine penicillin G IM 2.4mU 1 dose

or Doxycycline PO 100mg BD 14d

Question 9

late latent, unknown duration, tertiary syphilis treatment

Answer 9

Benzathine penicillin G IM 2.4mU once a week x 3 doses

or Doxycycline PO 100mg BD 28d

Question 10

neurosyphilis treatment

Answer 10

Crystalline penicillin G IV 3-4mU Q4h or 18-24mU/d as continuous infusion 10-14d
or
Procaine penicillin G IM 2.4mU daily plus probenacid PO 500mg QDS 10-14d

or
ceftriaxone IV/IM 2g Q24h 10-14d

Question 11

monitoring of syphilis treatment

Answer 11

jarisch-herxheimer reaction
primary/secondary: quantitative VDRL and RPR at 6 and 12m; decrease of titre by at least 4 folds
latent: 6, 12, 24m
neurosyphilis: CSF exam every 6m until normal