Syphilis

Aka: Syphilis, Treponema pallidum

1. See Also
   1. Sexually Transmitted Disease
   2. Primary Syphilis
   3. Secondary Syphilis
   4. Latent Syphilis
   5. Tertiary Syphilis
   6. Congenital Syphilis
   7. Syphilitic Gumma
   8. Cardiovascular Syphilis
   9. Neurosyphilis
   10. Syphilis Testing
   11. Genital Ulcer
2. Epidemiology
   1. Resurgence of Syphilis since HIV epidemic onset in 1980s
   2. Syphilis Incidence in U.S. (primary and secondary) is increasing
      1. 2000: 2.1 cases per 100,000 persons (5979 new cases in U.S.)
      2. 2005: 2.9 cases per 100,000 persons (8724 new cases in U.S.)
      3. 2010: 4.5 cases per 100,000 persons (13,774 new cases in U.S.)
      4. 2014: 6.3 cases per 100,000 persons (19,999 new cases in U.S.)
         1. Men account for 91% of cases (of whom 83% are Gay Men)
      5. 2015: 8.0 cases per 100,000 persons (23,872 new cases in U.S.)
3. Etiology
   1. Caused by Spirochete Treponema pallidum
   2. In addition to Syphilis, Treponema pallidum also causes yaws and pinta
4. Pathophysiology
   1. Transmission via mucous membranes, non-intact skin, transfusions, and vertical transmission (transplacental)
5. Risk factors: Cohorts with highest Prevalence in U.S.
   1. Homosexual men
   2. Males
   3. Southern and urban centers
   4. African americans
6. Signs: By Stage
   1. Primary Syphilis
      1. Solitary Chancre (hallmark ulcer of Primary Syphilis) - genital lesion in 95% of cases
         1. Single, painless, well-demarcated ulcer
         2. Clean base
         3. Indurated border
      2. Nonsuppurative, mildly tender Regional Lymphadenopathy (uncommon)
   2. Secondary Syphilis
      1. Nickel and dime-size pale, pink to red discrete round, ScalingMacular to papular lesions
         1. Distributed over trunk, flexors, palms, soles
      2. Condyloma Lata (painless, wart-like lesions)
         1. Distributed over mouth, genitalia and intertriginous areas (perineum, axilla, between toes)
      3. Syphilitic Alopecia (Alopecia with moth-eaten appearance)
   3. Latent Syphilis
      1. Latent, asymptomatic period of 3-20 years
      2. Infectious only in pregnancy and Blood Transfusion
      3. One third will progress to Tertiary Syphilis
   4. Tertiary Syphilis
      1. Syphilitic Gumma (granulomas and Psoriasis-like Plaques)
         1. Diffusely distributed soft ulcerative lesions, with firm necotic center
      2. Cardiovascular Syphilis (thoracic aneurysm)
      3. Neurosyphilis (Tabes Dorsalis, Meningitis, Dementia)
7. Differential Diagnosis
   1. See Genital Ulcer
   2. See Hand Dermatitis
   3. See Alopecia
   4. See Sexually Transmitted Infection
   5. Syphilis Chancre or Condyloma Lata
      1. Genital Herpes
      2. Chancroid
      3. Venereal Wart
      4. Lymphogranuloma venereum
8. Labs
   1. See Syphilis Testing
   2. HIV Screening
   3. Other Sexually Transmitted Infection sceening
      1. Gonorrhea PCR
      2. Chlamydia PCR
      3. Trichomonas PCR (or wet prep)
9. Precautions
   1. Syphilis requires a high index of suspicion
      1. Widely variable presentations
      2. Resurgence in the last 10 years
      3. Insidious and delayed onset with painless primary lesions that may easily be missed
10. Management
    1. Incubation stage (Post-exposure Prophylaxis)
       1. Ceftriaxone 250 mg IM and
       2. Doxycycline 100 mg for 14 days
       3. Azithromycin (Zithromax) 1 gram orally for 1 dose
    2. Primary, secondary, early latent (under one year)
       1. Benzathine Penicillin G
          1. Adult: 2.4 MU IM for 1 dose
          2. Child: 50,000 units/kg IM for 1 dose (max: 2.4 MU)
       2. Aqueous Procaine Penicillin G 0.6 MU IM qd for 8 days
       3. Jarisch-Herxheimer Reaction may occur
          1. Acute febrile reaction (due to Spirochete lysis) in first 24 hours of Syphilis treatment
          2. Manifests as fever, Headache, rash exacerbation
       4. If Penicillin allergic
          1. Ceftriaxone 1 gram IM or IV for 10-14 days
          2. Tetracycline 500 mg orally four times daily for 14 days
          3. Doxycycline 100 mg orally twice daily for 14 days
          4. Avoid Azithromycin
             1. Previously dosed at Azithromycin 2 grams orally once
             2. High risk of resistance (esp. pregnancy, Men who have Sex with Men)
             3. Was used only if Penicillin allergic and unable to take doxycyline, Minocycline or Ceftriaxone
    3. Late latent, Cardiovascular Syphilis (duration over 1 year)
       1. Benzathine Penicillin G 2.4 MU IM qWeek for 3 weeks
       2. If Penicillin allergic
          1. Tetracycline 500 mg PO qid for 4 weeks
          2. Doxycycline 100 mg PO bid for 4 weeks
    4. Neurosyphilis
       1. See Neurosyphilis
    5. Pregnancy
       1. Treat with Penicillin as above
       2. If Penicillin allergic, admit, desensitize and treat with Penicillin
    6. Congenital Syphilis
       1. CDC STD management booklet
          1. http://www.cdc.gov/mmwr/pdf/rr/rr5912.pdf
    7. Sexual partners
       1. Treat all sexual contacts from prior 90 days
11. Follow-up: 6 months after treatment (Stage 1-2)
    1. Repeat quantitative nontreponemal test titers at 6 and 12 months after treatment (all patients)
       1. Expect a four-fold decrease in RPR or VDRL titers over subsequent 3-6 months following treatment
       2. Four-fold increase in titers over prior level suggests recurrent Syphilis and these patients should be re-treated
       3. Decrease in titers may be slower in patients who have had more than one Syphilis infection
       4. Seronegative conversion may occur if original titers were low or in cases treated early (stage 1-2)
    2. Repeat clinical evaluation
       1. Persistent symptoms and signs despite treatment should prompt Syphilis re-treatment
12. References
    1. Green, Cohen, Billington (2016) Crit Dec Emerg Med 30(11): 4-10
    2. (2002) MMWR Morb Mortal Wkly Rep 51(RR-6):18-30 [PubMed]
    3. Brown (2003) Am Fam Physician 68(2):283-90 [PubMed]
    4. Hook (1999) Ann Intern Med 131:434-7 [PubMed]
    5. Mattel (2012) Am Fam Physician 86(5): 433-40 [PubMed]
    6. Workowski (2010) MMWR Recomm Rep 59(RR-12): 1-110 [PubMed]