Syphilis

• • Syphilis is caused by the Treponema. pallidum spirochete.

  • Primary syphilis may develop within several weeks of exposure and manifests as one or more painless, indurated, superficial ulcerations (chancre).

  • Secondary syphilis develops 4-10 wks after the chancre resolves and may produce a rash, mucocutaneous lesions, adenopathy, and constitutional sx.

  • Tertiary syphilis follows between 1 and 20 yrs after infection, and includes cardiovascular, gummatous, and neurologic disease (general paresis, tabes dorsalis, or menignovascular syphilis)

  • HIV coinfection is high. Rule this out.

Lab:

• • Primary syphilis, dark-field microscopy of the lesion exudates show organisms. A nontreponemal serologic test (RPR or VDRL) should be performed with a treponemal specific test (FTA-ABS, or T. pallidum particle agglutination)

  • Secondary syphilis dx is made on basis of serologic tests and clinical illness.

  • Latent syphilis is a serologic diagnosis in the absence of sx - early latent syphilis is serologically positive for < 1 year, and late latent syphilis is serologically positive for > 1 year.

Syphilis Tx:

• • Early syphilis: pts who are seroneg. and without si of syphilis, but who have been exposed to infection within previous 3 mo.

  • Latent syphilis: serological tests for syphilis +ve plus normal CSF plus asymptomatic.

  • Early latent: <1 y post inf. in untreated Pt.

  • Primary, secondary, or early latent < 1 year: Benzathine PCN G, 2.4 million units IM single dose. PCN allergic, nonpregnant: Doxycycline, 100 mg PO bid x 14 d; tetracycline, 500 mg PO qid x 14 d.

  • Late latent: >1 y or more post inf. in untreated Pt.

  • Tx of late latent, cardiovascular or benign 3° syphilis with normal CSF:

    • Pen G benzathine 2.4 MU IM weekly x 3 weeks. For PCN allergic pts: Tetracycline 500 mg PO qid or Doxycycline 100 mg PO bid x 4 weeks

  • 1°, 2°, or early latent syphilis: Pen G benzathine, give single dose of 2.4 MU IM (1.2 in each butt) cures 95% of cases.

  • Examine CSF from HIV-seropositive individuals with syphilis. If +ve Rx as in neurosyphilis

    • Aqueous pen G (procaine) 2.4 MU IM + probenicid 500 mg PO qid x 10 - 14 days; or

    • Aqueous pen-G 3 - 4 MU IV q4h x 10 - 14 days (total: 18 - 24 MU/d).

    • For Pts. allergic to PCNs: Patients must be desensitized to PCN, as neurosyphilis is only effectively treated with PCN. Tetracycline 500 mg PO qid or Doxycyline 100 mg PO bid x 2 weeks

  • Followup evaluation of responses to Tx in syphilis

  • Monitor VDRL and RPR titers: 1, 3, 6, and 12 mo after Rx.

  • In HIV + syphilis, VDRL and RPR titers: 1, 2, 3, 6, 9, & 12 mo.

  • Successful Tx: VDRL titers slowly declines, become negative in 12 mo.

  • If VDRL titer fails to fall at least 4 folds, within 12 mo, or if VDRL titer increase 4 fold, or clinical features persist, or recur: Retreat.

  • If CSF is abnormal, treat as in neurosyphilis.

  • If Pt stays sero +ve after Rx for neurosyphilis but asymptomatic, no further Rx is reqd.

  • The most sensitive index of response to Rx in neurosyphilis is degree of CSF pleocytosis.

ASx NS: No neurologic sx and si, but CSF abnl, including mononuclear pleocytosis, increased protein conc, or a reactive VDRL slide test. Seen in 1/4 of Pts with untreated latent syphilis. NS is associated with a RPR titer of >1:32 or more, regardless of clinical stage or HIV infection status.

Patient's with HIV and syphilis of >1 year's duration should undergo a lumbar puncture, for CSF studies, especially if the RPR titer if greater or equal to 1:32 and CD4 <350/uL

Neurosyphilis Tx:

Neurosyphilis is only effectively treated with penicillin.

Penicillin G 4 million units IV q.4 h. for 14 days. Follow up with benzathine penicillin 2.4 million units IM q. every week for 3 weeks.

Follow up response to treatment done with RPR. Check at 3-month, 6-

month, and 1-year after successful treatment RPR and VDRL should become negative by 1 year. Same non-treponemal test may be used in followup, as were used in original setting.

Pregnancy: PCN only recommended Tx. Desensitize Pt if needed.