MRCP revision battle 28.2: Syphillis

Syphilis is another of those conditions which is a common differential in MRCP questions.



Syphilis is caused by the spirochaete treponema pallidum.



There are 4 stages of syphilis:


1) Primary

• painless genital ulcer
• known as a chancre
• highly infectious

2) Secondary

• occurs 4-8 weeks after the chancre
• rash, malaise, lymphadenopathy, temperature
• condylomata lata

3) Tertiary syphilis

• >2yrs after secondary
• gummas (=granulomas) form in skin, mucosa and viscera

4) Quaternary syphilis

• cardiovascular
• aortic aneurysm
• aortic regurgitation
• neurosyphilis
• cranial nerve palsies
• general paralysis of the insane
• tabes dorsalis
• sensory ataxia
• numb legs
• lightening pains
• upgoing plantars
• argyll robertson pupil

Tests:

• cardiolipin antibody = VDRL, RPR
• not syphilis specific
• insensitive in late syphillis
• becomes negative after treatment
• false +ives in pregnancy, SLE, TB, leprosy, malaria, HIV
• treponeme-specific antibody = TPHA
• remains positive after treatment
• dark ground microscopy

Treatment:

• IM penicillin or PO doxcycline

Random eponymous warning - Jarisch-Herxheimer reaction:

• raised pulse, temp and vasodilation
• occurs hours after 1st dose of antibiotics
• due to release of endotoxin

Occurs in around 90% of patients with secondary syphilis.




Now on for a bit of third nerve palsy....