See also sections on "Syphilis in Pregnancy," "Congenital Syphilis"

I. Diagnosis: Darkfield or DFATP (serol. labeling) examination of chancre d/c; silver staining of bx material, FTA-ABS (serum serology), hemagglutination studies

II. Natural history: episodes of active disease with intervening periods of quiescence

  1. Primary: lesion is "chancre," a painless ulceration; appears about 3wk post-inf. & disappears spontaneously after 2-6 wks; accompanied by painless regional lymphadenopathy. Diff dx inc. HSV, chancroid, trauma with superinfection
  2. Secondary: Doesn't always occur. Us. starts after disappearance of chancre.
  1. Mucocutaneous sx (sore throat, "mucous patches" in oral & genital regions)
  2. Malaise, wt. loss
  3. Maculopapular rash on soles & palms; facial alopecia; intertriginous condylomata
  4. Rarely, glomerulonephritis, hepatitis with high alk-phos., proctitis, or conjunctivitis
  1. "Latent" phase: us. after 1yr of inf.; asymptomatic but still infectious
  2. Tertiary: Occurs in 33% of untreated cases, most path 2? to obliterative endarteritis
  1. Neurosyphilis: 2? to treponemes in CSF; may be asymptomatic or subacute, but typically
    1. Tabes dorsalis: 25-30y post-inf.; demyelination, paresis, mental status, hyperreflexia.
  2. CV changes (10-20y post-inf): inf. arteritis of aortic vasa vasorum; necrosis of tunica media
  1. "Henish-Herxheimer Rxn": to products of treponema lysis by PCN

III. Treatment

  1. Traditional tx = PCN IM or doxycycline x 2wks
  2. Syphilis-Azithromycin 2g single dose may be an alternative to penicilling G IM for primary, secondary, or early latent syphilis (J. Inf. Dis. 201:1729, 2010-JW)
  3. For postexposure prophylaxis, Azithromycin 1g IM may be as effective as PCN G Benzathine 2.4MU IM (study of 96 immunocompetent adults; Ann. Int. Med. 131:434, 1999--JW)