STD Toolkit


Primary Syphilis:

  • Painless chancre (ulcer) at site of infection
    • Usually appears about three weeks after infection (can be 10-90 days) and disappears about three to six weeks after that

Secondary Syphilis:

  • Macular rash (usually nonpruritic, and palmar and/or plantar)
  • Mucocutaneous lesions
  • Lymphadenopathy
  • Alopecia
  • Condylomata lata
  • Splenomegaly, sometimes liver and kidney involvement
  • Non-descript symptoms like fever, malaise, headache, sore throat, fatigue, muscle aches, and weight loss

Latent Syphilis:

  • No clinical manifestations

Tertiary (Late) Syphilis:

Can damage almost any part of the body, usually eyes, brain, heart, blood vessels, nerves, liver, bones, and joints

  • Gummas (soft, tumor-like growth)
    • Usually appear 10-15 years after initial infection 
  • Central nervous system lesions
  • Blindness
  • Mental illness
  • Deafness
  • Memory loss
  • Cardiovascular problems: aortic aneurysm, aortic insufficiency, or coronary ostial stenosis
    • Onset is usually 20-30 years after initial infection 


Can occur at any stage (usually a few months to a few years after infection), and may be asymptomatic

  • Meningitis
  • Cranial nerve dysfunction
  • Altered mental status
  • Loss of vibration sense
  • Auditory or ophthalmic abnormalities
  • Endarteritis with stroke-like symptoms and seizures
  • General paresis
  • Tabes dorsalis (demyelination of dorsal roots of the spinal cord)

Definitive Diagnosis:

  • Darkfield exam (or other tests) detecting T. pallidum in lesion exudate or tissue. Presumptive diagnosis may be made based on the combination of a positive treponemal test and non-treponemal test (a single test type is insufficient).

Routine testing recommended for:

  • Sexually active MSM
  • Pregnant women
  • High risk individuals (unprotected sex, commercial sex, resident of correctional facility) and especially for adolescents

    See US Preventative Services Task Force for more information.

There is no definitive diagnosis for congenital syphilis. Testing newborns for syphilis is not recommended as results may be non-reactive if the mother had a low titer or was infected in late pregnancy. Instead, a serum test is recommended to be performed on the mother.

Decision to treat should be based on:

  • identification of syphilis in the mother
  • adequacy of maternal treatment
  • presence of clinical, laboratory, or radiographic evidence of syphilis in the infant
  • comparison of maternal (at delivery) and infant nontreponemal serologic titers using the same test (preferably conducted by the same laboratory)

Please see the CDC's Sexually Transmitted Diseases Treatment Guidelines, 2015 for more detailed information on congenital syphilis, including determining when to treat and what treatment should be.

Primary, Secondary, and Early Latent Syphilis of Less Than 1 Year's Duration

Benzathine penicillin G, 2.4 million units IM in one dose


Doxycycline 100 mg orally 2 times a day for 14 days
Tetracycline 500 mg orally 4 times a day for 14 days

Late Latent Syphilis of More Than 1 Year's Duration, Latent Syphilis of Unknown Duration

Benzathine penicillin G, 7.2 million units total, given as 3 doses of 2.4 million units IM, 1 week apart for 3 consecutive weeks


Doxycycline, 100 mg orally 2 times a day for 28 days
Tetracycline, 500 mg orally 4 times a day for 28 days

Note: All patients should first be evaluated by a physician to exclude neurosyphilis.

Tertiary Syphilis (without neurosyphilis)

Benzathine penicillin G, 7.2 million units total, given as 3 doses of 2.4 million units IM, 1 week apart for 3 consecutive weeks


For patients allergic to penicillin, consult an infectious disease specialist.


Aqueous crystalline penicillin G 18-24 million units per day, administered as 3-4 million units IV every 4 hours or continuous infusion, for 10-14 days
Procaine penicillin 2.4 million units IM once daily &
Probenecid 500 mg orally four times a day, both for 10-14 days

Congenital Syphilis

Aqueous crystalline penicillin G 100,000-150,000 units/kg/day, administered as 50,000 units/kg/dose IV every 12 hours during the first 7 days of life and every 8 hours thereafter for a total of 10 days
Procaine penicillin G 50,000 units/kg/dose IM in a single daily dose for 10 days

Chancre on tongue
Chancre on tongue
Penile chancre
Penile chancre
Chancre on labia
Chancre on tongue
Adult Palmar/plantar rash
Adult Palmar/plantar rash
Secondary syphilis
generalized body rash
Secondary syphilis generalized body rash
Ulcerating gumma
Ulcerating gumma
Spirochetes in brain tissue
Spirochetes in brain tissue