Syphilis

Question 1

Clinical course of syphilis infection?

Answer 1

Primary: painless chancre/ulcer on genitals appearing 10-90d after infection and resolving in 4-6w

Secondary: 2-10w later - headache, lymphadenopathy, fever, myalgia, fatigue, rash (hands and feet); resolves in 3-6w

Latency: slow treponemal replication

Tertiary: 3-15y later - cardiac, late neurosyphilis, gummatous destruction

Question 2

Treatment of syphilis?

Answer 2

Early: benzathine penicillin G 2.4 million U IM once; (if pregnant, can do a 2nd dose in 1 wk)

Greater than 1 year duration: pen G 2.4 million U IM weekly for 3 doses

Neurosyphilis: aqueous crystalline pen G 18-24 million U daily, administered as 3-4 million units IV q4h or continuous for 10-14d
OR
procaine penicillin 2.4 million U IM qd, plus probenecid 500 mg PO qid, both for 10-14d

Tetracyclines, cephalosporins, and azithromycin are options if not pregnant - not good in pregnancy due to increased resistance to these drugs and inadequate placental passage - only penicillin is good and have to desensitize those with allergies

Question 3

Risk of vertical transmission in pregnant women with syphilis?

Answer 3

60% in primary syphilis, almost 100% in secondary syphilis, 10% with latent syphilis

Question 4

Symptoms of intrauterine infection with syphilis (both in utero and in neonate)?

Answer 4

Premature labor, hydrops fetalis, fetal death (in utero)

In neonate: snuffles (rhinorrhea), hepatosplenomegaly, rash, low birth weight, hearing loss, fourfold higher titers on neonatal RPR test - risk is higher in women who are incompletely treated or if tx occurs <30d before delivery

Question 5

Diagnosis of syphilis?

Answer 5

Screening: VDRL or RPR test (antibody screen but can be false positive with other infections and in pregnancy)

Confirmatory: fluorescent treponemal antibody or T Pallidum particle agglutination test

Question 6

A 25-year-old woman, gravida 1, at 10 weeks of gestation comes to your office for prenatal care. Her rapid plasma reagin (RPR), non-specific treponemal antibody test was reactive with a titer of 1:16. She also had a positive treponemal specific test result. Other prenatal laboratory results were unremarkable. The patient has mild nausea but no other medical problems. She has a normal physi- cal examination. She has a history of anaphylaxis with penicillin administration for streptococcal pharyngitis (“strep throat”) 5 years ago, but she can tolerate cephalexin. The best treatment option is:

(A) tetracycline
(B) azithromycin
(C) penicillin G desensitization
(D) ceftriaxone

Answer 6

(C) penicillin G desensitization