STIs

Question 1

STIs presenting with discharge (5)

Answer 1

Gonorrhea, 
Chalmydia, 
Trichomonas, 
Candida, 
Bacterial vaginosis.

Question 2

STIs presenting with ulceration (5)

Answer 2

Painful: 
 - Herpes simplex, 
 - Chancroid 
Painless: 
 - Syphilis, 
 - LGV 
 - Donovanosis (= granuloma inguinale = Klebsiella granulomatis).

Question 3

Presenting with lumps or rashes

Answer 3

Genital warts (HPV),
Molluscum contagiosum,
Scabies,
Pubic lice.

Question 4

Gonorrhoea:

Organism, Dx, Tx

Answer 4

Neisseria gonorrhoeae - intracellular G- diplococcus.
Gold standard: urine NAAT (PCR or similar).
Used to be culture from swabs.
IM ceftriaxone 500mg stat
+ 1g azithromycin stat
or (old): + 100mg doxycycline bd for 2 weeks.

Question 5

Complications of Gonorrhoea

Answer 5

Bartholin's abscess, 
Dissemination if complement def, 
Ophthalmia neonatorum (neonatal conjunctivitis).

Question 6

Chlamydia -

Organism and serovars

Answer 6

Chlamydia trachomatis - Intracellular G- bacterium.
Serovars Ab, B, Ba, C: trachoma (eyes);
D-K: Genital chlamydia (urethritis, PID) and ophthalmia neonatorum.
L1-3: LGV.

Question 7

Complications of genital Chlamydia

Answer 7

• PID in 30% (involved in half of PID)
• Tubal factor infertility
• Ectopic pregnancy x9
• Endometriosis
• Reiter’s syndrome
• Ophthalmia neonatorum and adult conjunctivitis

Question 8

Chlamydia Dx and Tx

Answer 8

Urine NAAT.
Azithromycin 1g stat
(or Doxycycline 100mg bd for a week)
Partner notification and test for other STIs.

Question 9

LGV - what is it and who gets it?

Answer 9

Lympho-granuloma venereum - serovars L1-3 of Chlamydia trachomatis.
MSM, or anyone abroad.

Question 10

Stages of LGV

Answer 10

1: 3-12 days, painless ulcer, inflam.
2: 2 weeks, Painful inguinal buboes, can rupture. Fever, malaise, proctocolitis (pain, tenesmus, bleeding, d/c).
Late: Inguinal LN, abscesses, genital elephantiasis, frozen pelvis, rectal strictures.

Question 11

LGV - Dx and Tx

Answer 11

Chlamydia NAAT then genotypic identification of serovar by PCR.
Doxycycline 100mg bd for 3 weeks.

Question 12

Syphilis - organism

Answer 12

Treponema pallidum
G- spirochaete
Seen in primary lesions on dark background microscopy..

Question 13

Syphilis - Test for current infection / success of treatment

Answer 13

Detect generic Antigens - VDRL and RPR.

Question 14

Syphilis - Test which stays positive for years after infection

Answer 14

Detect Abs.
eg. Enzyme immunoassay, Fluorescent treponemal Ab, T p haemagglutination test, T p particle agglutination test.
More specific.

Question 15

Primary Syphilis - features

Answer 15

One macule, then papule, then indurated painless ulcer.
Can stay for 4-6 weeks (chancre).
Clean base with serous exudate.
Regional LN.

Question 16

Secondary Syphilis - features

Answer 16

Systemic bacteraemia
1-6 months after infection.
Low grade fever, malaise.
Rash: symmetrical, non-pruritic, everyhwere, maculopapular.
Snail track oral ulcers, uveitis, alopecia, warts. Neuro involvement.
“The great imitator”

Question 17

Tertiary Syphilis - features

Answer 17

• Neurosyphilis (in HIV) 2-30 years later. Argyll-Robertson pupil (accomodates but does not react). General paresis of the insane.
• Gumma (granuloma) - rare. Type IV reaction 2-40 years later.
• Cardiovascular - inflam aortitis 2-30 years later, lots of spirochaetes.

Question 18

Tx for Syphilis

Answer 18

Benzathine penicillin with procaine IM, stat.
(Doxycycline if allergic.)
4x reduction in RPR = success.
NB. Jarish-Heimer reaction on the day - rash, fever etc.

Question 19

Chancroid -

Organism, feature, Dx

Answer 19

Haemophilus ducreyi (G- coccobacillus, like HiB). 
Tropical ulcers (rare in UK), multiple, painful. 
Dx by culture (chocolate agar) and PCR.

Question 20

Donovanosis -

name, organism, geography, features, Dx, Tx

Answer 20

= granuloma inguinale,
by Klebsiella granulomatis (G- bacillus).
Africa, India, PNG, Australian aborigines.
Papule/nodule breaks down into large expanding ulcer. Beefy red.
Dx by Giemsa stain of biopsy, or tissue crush.
Tx: azithromycin.

Question 21

Trichomoniasis

Answer 21

Trichomonas vaginalis - flagellated protozoan.
Discharge in woman. ^ risk of acquiring HIV.
Dx: wet prep microsopy, PCR.
Tx: metronidazole.

Question 22

Bacterial vaginosis

Answer 22

Abnormal flora, many microbes, few lactabacilli.
Discharge, odour.
Not sexually transmitted. ?too rigorous hygeine.
Dx: Gram stain, whiff test, clue cells, raised pH.
Assoc preterm delivery.

Question 23

Candidiasis

Answer 23

Usually candida albicans.
Thick white discharge, itching, red, sore.
Not sexually transmitted.
Tx: Topical or oral fluconazole.

Question 24

Molluscum contagiosum

Answer 24

dsDNA poxvirus.
Hands and faces in children, skin to skin contact. Genital lesions in adults (so sexual contact).
Facial molluscum in adults = HIV.
Cryotherapy if required.

Question 25

Genital warts

Answer 25

HPV 6, 11.
Incubation 3 weeks to 8 months.
Papular, planar, pedunculated, keratinised.
Podophyllotoxin / imiquimod / cryo.