STIs

Question 1

DDx for GU ulcerated disease (include bugs where applicable)? (9)

Answer 1

1) Genital herpes
2) Primary syphilis (Treponema pallidum, GN)
3) Chancroid (Haemophilus ducreyi)
4) Trauma
5) Granuloma inguinale (Klebsiella granulomatis)
6) Lymphogranuloma venereum (invasive seovars L1, L2/2a, L3 of chlamydia)
7) Abscess
8) Neoplasm
9) Behcet’s (small + large vessel vasculitis)

Question 2

DDx for GU discharge? What types of bugs are these? (9)

Answer 2

1) Gonorrohea (Neisseria gonorrheae, GN aerobic bacteria)
2) Chlamydia (weak GN, obligate IC bacteria)
3) Nongonococcal urethritis (NGU - chlamydia, ureaplasma urealyticum, mycoplasma genitalium, etc)
4) Trichomoniosis
5) BV (multiple bact, typically starts with Gardnerella vaginalis)
6) Candida vaginitis
7) PID (typically multibacterial)
8) Foreign Body
9) Irritants/allergens

Question 3

DDx for GU epithelial cell lesions? (6)

Answer 3

1) Genital warts (HPV 6, 11)
2) Secondary syphilis (T. pallidum)
3) Molluscum Contagiosum (this virus, a poxvirus)
4) Neoplasm
5) Nevi
6) Skin Tags

Question 4

Which type of HSV is more likely to occur?

Answer 4

HSV-2 recurs more than HSV 1

Question 5

How long does a primary HSV infection last?

Answer 5

Typically 2-4 weeks, spont resolution

Question 6

Management of genital herpes? (4 options)

Answer 6

Acyclovir 400 mg TID x 7-10d
Acyclovir 200 mg 5x/d
Valacyclovir 1000mg BID
Famiciclovir 250 mg TID

Question 7

What is primary syphilis? How can it present? (6)

Answer 7

• Chancre - usually single lesion
• at site of spirochete inoculation (usually MM of mouth or genitalia, may also be anorectal).
• begins as papule develops –> ulcer ~ 1 cm with clean base + raised borders
• painless (unless 2o infection)
• +/- painless LN

Question 8

How do you diagnose syphillis? (3)

Answer 8

1] Dark-field microscopy
2] Nonspecific nontreponemal (VDRL, RPR) – 70-80% 1o syphilis may be negative early, near 100% in 2o
3] Treponemal (FTA-abs –> most specific + sensitivity, MHA-TP)

Question 9

What are the sx of secondary syphilis (6)? What percentage get this phase and at what time?

Answer 9

• Maculopapular rash (classically palms + soles)
• Generalized LN’y
• Malaise
• Alopecia
• Condyloma lata (moist, flat, verrucous – ++ contagious)

–> 25% get, typically 6 weeks + (rarely can overlap 1o syph)

Question 10

What are the presentations of tertiary syphilis? (3) What is risk of progression?

Answer 10

25-40% progress if untreated.

• CV manifestations - syphilitic aortitis +/- aneurysm
• Gummatous disease (tumour like inflammatory balls - most common skin, bone, liver)
• Neurosyphilis

Question 11

What is the treatment of syphilis? (3)

Answer 11

Primary + secondary + early latent = benzanthine pen G 2.4 mil U IM
late latent = benzanthine pen G 2.4 mil U IM Qweekly x 3
neurosyphilis = aqueous pen G 3-4 units IV q4H x 10-14d

Question 12

What is a complication of the treatment of syphilis and what is management? What other diseases can cause this (2)?

Answer 12

Jarisch-Herxheimer reaction = rxn to endotoxin like products of syphilis (and other spirochetes - lyme, relapsing fever = Borrelia, leptospirosis)

Question 13

What are alternative treatments for syphilis e.g. if pen allergic? (4 + 2)

Answer 13

1o/2o/early latent =

• doxycycline 100 mg PO BID x 14d
• tetracycline 500 mg PO QID x 14d
• CTX 1g IM/IV OD x 10-14d
• azithromycin 2g m PO x 1 ( increasing resistance)

neurosyphilis =

• benz pen G 2.4 IM q24h x 10-4d AND probenecid 0.5g PO QID x 10-14d
• or CTX 2 g IM/IV q24 x 14d (25% failure rate)