Treatment may lead to Jarisch-Herxheimer reaction caused by the lysis of treponeme which releases endotoxin-like factors leading to fever, chills and myalgias.  SLE and infectious mononucleosis patients can have false-positive VDRL tests due to anti-cardiolipin antibodies.  With these individuals clarification is achieved through the use of the more specific FTA-ABS test.  Syphilis meningitis presents with increased lymphocytes but normal PMNs in the CSF.  Treponema pallidum subspecies cause nonvenereal skin ulcers and skin/bone gummas: T. pallidum endemicum causes endemic syphilis (common in Africa and the Middle East), T. pallidum perfenue causes Yaws (gummas disfigure the face), T. pallidum carateum causes Pinta (red to blue to white lesions limited to Latin America).


Diseases that cause palm and sole rashes:

  • Syphilis
  • RMSF
  • Coxsackievirus infections

Organisms that cross the placenta and therefore allows infection to pass from the pregnant mother to the fetus are as follows:




HErpes, HIV



Clinical presentation:

  • Primary (1°) syphilis – painless chancre
  • Secondary (2°) syphilis – condyloma lata; maculopapular rash on palms and soles; meningitis, hepatitis, arthritis, and others.
  • Tertiary (3°) syphilis – gummas (granulomas of the soft tissue and bone).  Within the CV system this can lead to aoritis and ascending aortic aneurysm.  Within the CNS this can lead to tabes dorsalis, general paralysis, meningitis, Argyll Robertson pupil (accommodates to near objects but does not react to light), congenital syphilis – CN VIII deafness, mulberry molars, saber shins, saddle nose, and Hutchinson’s incisors.

Pathology:  humans are the only host of this microorganism.  It is transmitted from skin lesions containing spirochetes (sexual or casual contact).  From here the spirochete penetrates mucous membranes and spreads systemically within hours of inocculation.

  • In 1° syphilis (visible up to 6 weeks after exposure) the organism replicates at the inoculation site generating a painless chancre (ulcerated lesion shedding spirochetes).  This lesion heals spontaneously over 6 weeks.
  • In 2° syphilis (visible for up to 6 weeks after the chancre heals)  the disseminated spirochetes continue to proliferate and form lesions throughout the body including condyloma lata (wart-like painless lesions in moist areas like the genitals.  These lesions may heal spontaneously or may become latent syphilis (no symptoms but serologically positive).  Cycles of 2° syphilis can repeat multiples times.
  • In 3° syphilis (many years later) the individual suffers from chronic inflammation against the remaining spirochetes.  This causes damage to soft tissue and bone (gummas), the CV system (aoritis) and the CNS.

Transplacental transmission is possible which leads to congenital syphilis which results in stillbirth or fetal abnormalities.

Diagnosis:  dark-field microscopy (spirochetes not visible by Gram stain), serological tests.  VDRL (nonspecific) – detects reagin antibodies against cardiolipin.  FTA-ABS (specific) – detects anti-treponemal antibodies.

Treatment:  Penicillin G