STI's

Question 1

major presenting complaints

Answer 1

urethral discharge/dysuria (urethritis)
vaginal discharge
genital ulcers/sores
lumps and bumps

Question 2

urethritis

Answer 2

Sx: urethral discharge, dysuria
signs: urethral discharge (evident or not)m, meatitis

Question 3

aetiology of urethritis

Answer 3

neisseria gonorrhoea
chlamydia trachomatis
mycoplasma genitalum (non specific urethritis, NSU)
ureaplasma urealyticum (NSU)
HSV
trichomonas vaginalis (TV)

Question 4

diagnosis of urethritis

Answer 4

1. gram stain: >5 pus cells/high power field = urethritis
2. look for gram negative intracellular diplococci (if none found, then non-gonococcal urethritis)
3. culture and sensitivity for N. gonorrhoea (urethral sample)
4. combined PCR for gonorrhoea and chlamydia (urine or urethral sample)

PCR is more sensitive than cultures for gonorrhoea, but gives no ABx sensitivity data

Question 5

urethritis Tx

Answer 5

uncomplicated gonorrhoea:
ceftriaxone 500mg IM with azithromycin 1g single dose, witnessed
ciprofloxacin 400mg oral (if known sensitive)
ofloxacin 400mg oral

uncomplicated chlamydia/NSU:
doxycycline 100mg twice daily for 1 week
azithromycin 1g stat oral

contact tracing is a vital part of management

Question 6

complications of urethritis

Answer 6

epididymo-orchitis/(prostatitis)
PID
local abscess formation (eg batholinitis)
disseminated gonococcal infection
fitz-hugh curtis syndrome (perihepatitis)
transmission to neonate - ophthalmia neonatorum, mucous membrane infections, pneumonitis

Question 7

fitz-hugh curtis syndrome

Answer 7

a rare complication of PID involving the liver capsule inflammation leading to adhesions

Question 8

causes of genital ulceration

Answer 8

infections
trauma
immune mediated
neoplastic
misc.

Question 9

ulcers caused by STIs

Answer 9

HSV
syphilis (primary and tertiary)
tropical STIs (chancroid, lymphogranuloma, venereum (LGV)/granuloma inguinale)
scabies - if secondary infection

Question 10

genital herpes simplex

Answer 10

type 1 and 2
transmission: oral, genital - direct contact
asymptomatic carriers are a common source for transmission
in the first episode there will be severe Sx
recurrences are common (approx. 50-70%), but with milder Sx

Question 11

diagnosis HSV

Answer 11

Hx
clinical appearance
virus demonstration on PCR
serology - retrospective diagnosis, no use in routine clinical practice

Question 12

Tx HSV

Answer 12

primary/first episode:
immediate Tx with aciclovir 400mg tds or aciclovir 200mg x 5, for 5 days
analgesia - topical gel and oral

recurrences:
supportive
episodic standby antiviral
continuous suppressive antivirals - usually with aciclovir 400mg tablets

Question 13

syphilis

Answer 13

spirochete called treponema pallidum
wide DDx
may present with rashes, ulcers, lymphadenopathy, abnormal LFTs etc
can be asymptomatic

Question 14

stages of syphilis

Answer 14

early (infectious) <2y:
primary, secondary, early latent

late (non-infectious) >2y:
late latent
cardiovascular
neurosyphilis
gummatous

Question 15

diagnosis of syphilis

Answer 15

1. primary - dark ground microscopy or PCR
2. serological tests (STS):
   non-specific tests: VDRL
   specific tests: treponemal IgG enzyme-linked immunosorbent assay (EIA)
   2nd line EIA
   treponema pallidum particle agglutination assay (TPPA)
   IgM
3. always repeat a positive for confirmation

Question 16

Tx syphilis

Answer 16

1st line: 2.4 megaunits benzathine benzyl penicillin (8ml injection)
2nd line or penicillin allergy: doxycycline

duration of Tx depends on the stage

Question 17

lumos caused by STIs

Answer 17

genital warts
secondary syphilis
molluscum contagiosum
scabies

Question 18

genital warts

Answer 18

HPV types 6 and 11
carrier status/subclinical infection
recurrences common
cervical cancer from high risk HPV types 16 and 18
cervical cancer vaccine - quadrivalent against 6,11 (low risk - warts) and 16 and 18 (high risk - cancer)

warts are painless, and diagnosed clinically. if any doubt - biopsy

Question 19

warts treatment options

Answer 19

depend on size and number
ablative therapy: podophyllotoxin (cream), cryotherapy, surgical removal
immune modulation: imiquimod

no treatment is an option

Question 20

vaginal discharge - vaginitis/vaginosis

Answer 20

bacterial vaginosis
candidiasis
trichomoniasis

Question 21

bacterial vaginosis

Answer 21

Sx:
discharge
malodour
feeling ‘dirty’

overgrowth of predominantly anaerobic bacteria especially gardnerella vaginalis and lactobacilli will disappear
not necessarily sexually transmitted
commoner in IUCD users

Question 22

diagnosis BV

Answer 22

malodourus, thin, homogenous vaginal discharge
‘clue cells’ and mixed flora on vaginal wet film or gram smear

Tx: not necessary if asymptomatic
metronidazole 400mg BD for 5-7 days

Question 23

candidiasis

Answer 23

Sx: itch, dry, lumpy, ‘yeaty smell’
diagnosis: clinical suspicion - typically causes causes vulvo-vaginitis with fissuring and thick, white, lumpy, nn-smelly vaginal discharge
identification of spores and pseudohyphae on gram stained vaginal smear or wet film

Question 24

precipitating factors for candidiasis (not all cases)

Answer 24

pregnancy
DM
broad spectrum ABx
anaemia
immunosuppression
endocrine disorders eg thyroid, parathyroid, adrenal
irritants eg antiseptics, bath additives
poor hygiene

Question 25

Tx of candidiasis

Answer 25

clotrimazole vaginal pessary 500mg stat or single dose fluconazole (150mg)
clotrimazole 1% cream if vulvitis

recurrent episodes:
investigate for predisposing factors
confirm diagnosis and ‘type’ candida
a longer course of fluconazole (every 3 days, the 3x weekly)
longer course of pessaries
genital hygiene advice- emollients, simple products

Question 26

trichomoniasis vaginalis

Answer 26

vulvo-vaginitis - offensive vaginal discharge, often green or yellow
asymptomatic in men
usually sexually transmitted
diagnosis: identification of the motile protozoan on a wet mount vaginal sample

Question 27

Tx of trichomoniasis

Answer 27

uncomplicated infection: metronidazole 400mg BDX for 7 days
OR
metronidazole 2g PO stat
NB safe in pregnancy