II. Epidemiology
- Resurgence of Syphilis since HIV epidemic onset in 1980s
- Worldwide: 5 Million new cases per year
- Syphilis Incidence in U.S. (primary and secondary) is increasing
- 2000: 2.1 cases per 100,000 persons (5979 new cases in U.S.)
- 2005: 2.9 cases per 100,000 persons (8724 new cases in U.S.)
- 2010: 4.5 cases per 100,000 persons (13,774 new cases in U.S.)
- 2014: 6.3 cases per 100,000 persons (19,999 new cases in U.S.)
- Men account for 91% of cases (of whom 83% are Gay Men)
- 2015: 8.0 cases per 100,000 persons (23,872 new cases in U.S.)
- 2018: 10.8 cases per 100,000 persons (35,063 new cases in U.S.)
- Gender
- Syphilis infections in women is increasing as of 2021
- High risk of Congenital Syphilis for women who are infected with Syphilis during pregnancy
- Screen high risk patients in pregnancy at intake, 28 weeks and at delivery
- Males account for 90% of cases
- Men who have Sex with Men account for 82% of cases in men
- More common in men of color under age 30 years
- HIV and Syphilis infection are associated
- Syphilis infections in women is increasing as of 2021
- Reinfections
- Reinfection accounts for 15-20% of new Syphilis cases each year
III. Causes
- Caused by Spirochete Treponema pallidum
- In addition to Syphilis, Treponema pallidum also causes yaws and pinta
IV. Pathophysiology
- Transmission via mucous membranes, non-intact skin, transfusions, and vertical transmission (transplacental)
V. Risk factors: Cohorts with highest Prevalence in U.S.
- HIV Infection
- Men who have Sex with Men (most common)
- Incarceration
- Sex Worker History
- Males
- Southern and Western U.S,
- Urban centers
- Age 20 to 35 years (esp. under age 30 years old)
- Race and ethnicity
- African americans
- Hispanics
- American Indians
- Alaskan and Hawaiian natives
- Pacific Islanders
VI. Signs: By Stage
- Early Syphilis
- Primary Syphilis
- Solitary Chancre (hallmark ulcer of Primary Syphilis)
- Genital lesion present in 95% of cases (Oral Mucosa ulcer in remainder of cases)
- Single, painless, well-demarcated ulcer
- Clean base
- Indurated border
- Nonsuppurative, mildly tender Regional Lymphadenopathy (uncommon)
- Solitary Chancre (hallmark ulcer of Primary Syphilis)
- Secondary Syphilis
- Nickel and dime-size pale, pink to red discrete round, ScalingMacular to papular lesions
- Distributed over trunk, flexors, palms, soles
- Condyloma Lata (painless, wart-like lesions)
- Distributed over mouth, genitalia and intertriginous areas (perineum, axilla, between toes)
- Syphilitic Alopecia (Alopecia with moth-eaten appearance)
- Nickel and dime-size pale, pink to red discrete round, ScalingMacular to papular lesions
- Primary Syphilis
- Late Syphilis
- Latent Syphilis
- Latent, asymptomatic period of 3-20 years
- Infectious only in pregnancy and Blood Transfusion
- One third will progress to Tertiary Syphilis
- Tertiary Syphilis
- Syphilitic Gumma (Granulomas and Psoriasis-like Plaques)
- Diffusely distributed soft ulcerative lesions, with firm necotic center
- Cardiovascular Syphilis (thoracic aneurysm)
- Neurosyphilis (Tabes Dorsalis, Meningitis, Dementia)
- Syphilitic Gumma (Granulomas and Psoriasis-like Plaques)
- Latent Syphilis
VII. Differential Diagnosis
VIII. Labs
- See Syphilis Testing
- HIV Screening
- Other Sexually Transmitted Infection sceening
- Gonorrhea PCR
- Chlamydia PCR
- Trichomonas PCR (or Wet Prep)
IX. Precautions
- Test in pregnancy at intake
- Risk of Congenital Syphilis
- Repeat testing at 28 weeks and after delivery in high risk patients
- Syphilis requires a high index of suspicion
- Widely variable presentations
- Resurgence in the last 10 years
- Insidious and delayed onset with painless primary lesions that may easily be missed
- Syphilis course is complex
- Neurologic complications may occur at any stage of illness
- Latent periods of infection are common (despite ongoing infection)
- Late Syphilis (latent and Tertiary Syphilis) are high risk if Syphilis is not treated in the first year of infection
X. Management: General
- Precautions
- Do NOT use Bicillin CR (short acting preparation) to treat Syphilis
- Evaluate for ear, eye or neurologic findings (requires admission and IV Penicillin for 14 days)
- Incubation stage (Post-exposure Prophylaxis)
- Gonorrhea and Syphilis Prophylaxis
- Ceftriaxone 500 mg IM/IV for 1 dose (1 gram IM/IV if weight > 150 kg, dose increased in 2020)
- Chlamydia and Syphilis Prophylaxis
- Doxycycline 100 mg twice daily for 7 days (preferred as of 2020)
- References
- Gonorrhea and Syphilis Prophylaxis
- Primary, secondary, early latent (under one year)
- Benzathine Penicillin G (Bicillin LA)
- Adult: 2.4 MU IM for 1 dose
- Child: 50,000 units/kg IM for 1 dose (max: 2.4 MU)
- Aqueous Procaine Penicillin G 0.6 MU IM daily for 8 days
- Jarisch-Herxheimer Reaction may occur
- Acute febrile reaction (due to Spirochete lysis) in first 24 hours of Syphilis treatment
- Manifests as fever, Headache, rash exacerbation
- If Penicillin allergic
- Ceftriaxone 1 to 2 gram IM or IV for 10-14 days
- Tetracycline 500 mg orally four times daily for 14 days
- Doxycycline 100 mg orally twice daily for 14 days
- Avoid Azithromycin
- Previously dosed at Azithromycin 2 grams orally once
- High risk of resistance (esp. pregnancy, Men who have Sex with Men)
- Was used only if Penicillin allergic and unable to take doxycyline, Minocycline or Ceftriaxone
- Benzathine Penicillin G (Bicillin LA)
- Late latent, Cardiovascular Syphilis (duration over 1 year)
- Benzathine Penicillin (Bicillin LA) G 2.4 MU IM weekly for 3 weeks
- If Penicillin allergic
- Tetracycline 500 mg orally four times daily for 4 weeks OR
- Doxycycline 100 mg orally twice daily for 4 weeks
-
Neurosyphilis
- See Neurosyphilis
- Pregnancy
- Screen all patients in early pregnancy (and consider rescreening in third trimester)
- Identifying maternal Syphilis before 4 months gestation prevents Congenital Syphilis
- Treat with Penicillin as above
- If Penicillin allergic, admit, desensitize and treat with Penicillin
- Consider hospital admission for start of treatment
- Risk of Preterm Labor associated with Jarisch-Herxheimer Reaction
-
Congenital Syphilis
- CDC STD management booklet
- Sexual partners
- Treat all sexual contacts from prior 90 days
XI. Management: Follow-up at 6 months after treatment
- Prior Syphilis does not result in significant Immunity to prevent reinfection
- If exposure risks remain unchanged, reinfection is common
- Repeat quantitative nontreponemal test titers at 6 and 12 months after treatment (all patients)
- Expect a four-fold decrease in RPR or VDRL titers over subsequent 3-6 months following treatment
- Four-fold increase in titers over prior level suggests recurrent Syphilis and these patients should be re-treated
- Decrease in titers may be slower in patients who have had more than one Syphilis infection
- Seronegative conversion may occur if original titers were low or in cases treated early (stage 1-2)
- Repeat clinical evaluation
- Persistent symptoms and signs despite treatment should prompt Syphilis re-treatment
- Extended follow-up for late Syphilis (latent, tertiary) and neurologic complications
- Additional follow-up at 12 and 24 months for latent and Tertiary Syphilis
- Additional follow-up at 3 months, and continue every 6 months until CSF labs normalize
XII. Complications
- Unteated pregnancy (even if acquired up to 4 years before pregnancy)
- Congenital Syphilis (fetal infection risk 80%)
- Stillbirth or Miscarriage: 40%
- Untreated Secondary Syphilis
- Lues Maligna (Ulceronodular Syphilis, Malignant Syphilis)
- Severe form of Secondary Syphilis (especially in immunosuppressed patients)
- Hepatitis
- Periostitis
- Nephropathy
- Uveitis or Iritis
- Lues Maligna (Ulceronodular Syphilis, Malignant Syphilis)
- Untreated Tertiary Syphilis
- Thoracic Aortic Aneurysm (from ascending aortitis)
- Neurosyphilis complications
-
HIV Transmission
- Syphilis related Genital Ulcers (Chancre of Primary Syphilis) facilitate HIV Transmission
- Chancres are laden with Lymphocytes which allow for both HIV Transmission and entry
XIII. Prevention
-
Personal Protection Equipment (PPE)
- Use contact precautions
- T. pallidum infects host via mucous membranes and nonintact skin (as well as hematologic)
- Chancre (Primary Syphilis) and Condyloma Lata (Secondary Syphilis) are contagious lesions
- Screen all high risk patients at least annually
- Screen more often in Men who have Sex with Men, not in monogamous relationships
- Screen in pregnancy
- Screen at least once in pregnancy (typically with initial pregnancy labs, and consider repeat at 28 weeks)
- Repeat screening in high risk groups and in regions of high syphilis Prevalence
XIV. References
- Green, Cohen, Billington (2016) Crit Dec Emerg Med 30(11): 4-10
- Kirk, McHugh and Parnell (2023) Crit Dec Emerg Med 37(8): 23-9
- (2002) MMWR Recomm Rep 51(RR-6):1-78 +PMID: 12184549 [PubMed]
- Brown (2003) Am Fam Physician 68(2):283-90 [PubMed]
- Hook (1999) Ann Intern Med 131:434-7 [PubMed]
- Mattel (2012) Am Fam Physician 86(5): 433-40 [PubMed]
- Ricco (2020) Am Fam Physician 102(2): 91-8 [PubMed]
- Workowski (2010) MMWR Recomm Rep 59(RR-12): 1-110 [PubMed]
- Workowski (2021) MMWR Recomm Rep 70(4): 1-187 [PubMed]