STI's Flashcards
major presenting complaints
urethral discharge/dysuria (urethritis)
vaginal discharge
genital ulcers/sores
lumps and bumps
urethritis
Sx: urethral discharge, dysuria
signs: urethral discharge (evident or not)m, meatitis
aetiology of urethritis
neisseria gonorrhoea chlamydia trachomatis mycoplasma genitalum (non specific urethritis, NSU) ureaplasma urealyticum (NSU) HSV trichomonas vaginalis (TV)
diagnosis of urethritis
- gram stain: >5 pus cells/high power field = urethritis
- look for gram negative intracellular diplococci (if none found, then non-gonococcal urethritis)
- culture and sensitivity for N. gonorrhoea (urethral sample)
- combined PCR for gonorrhoea and chlamydia (urine or urethral sample)
PCR is more sensitive than cultures for gonorrhoea, but gives no ABx sensitivity data
urethritis Tx
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
complications of urethritis
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
fitz-hugh curtis syndrome
a rare complication of PID involving the liver capsule inflammation leading to adhesions
causes of genital ulceration
infections trauma immune mediated neoplastic misc.
ulcers caused by STIs
HSV
syphilis (primary and tertiary)
tropical STIs (chancroid, lymphogranuloma, venereum (LGV)/granuloma inguinale)
scabies - if secondary infection
genital herpes simplex
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
diagnosis HSV
Hx
clinical appearance
virus demonstration on PCR
serology - retrospective diagnosis, no use in routine clinical practice
Tx HSV
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
syphilis
spirochete called treponema pallidum
wide DDx
may present with rashes, ulcers, lymphadenopathy, abnormal LFTs etc
can be asymptomatic
stages of syphilis
early (infectious) <2y:
primary, secondary, early latent
late (non-infectious) >2y: late latent cardiovascular neurosyphilis gummatous
diagnosis of syphilis
- primary - dark ground microscopy or PCR
- 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 - always repeat a positive for confirmation
Tx syphilis
1st line: 2.4 megaunits benzathine benzyl penicillin (8ml injection)
2nd line or penicillin allergy: doxycycline
duration of Tx depends on the stage
lumos caused by STIs
genital warts
secondary syphilis
molluscum contagiosum
scabies
genital warts
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
warts treatment options
depend on size and number
ablative therapy: podophyllotoxin (cream), cryotherapy, surgical removal
immune modulation: imiquimod
no treatment is an option
vaginal discharge - vaginitis/vaginosis
bacterial vaginosis
candidiasis
trichomoniasis
bacterial vaginosis
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
diagnosis BV
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
candidiasis
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
precipitating factors for candidiasis (not all cases)
pregnancy DM broad spectrum ABx anaemia immunosuppression endocrine disorders eg thyroid, parathyroid, adrenal irritants eg antiseptics, bath additives poor hygiene
Tx of candidiasis
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
trichomoniasis vaginalis
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
Tx of trichomoniasis
uncomplicated infection: metronidazole 400mg BDX for 7 days
OR
metronidazole 2g PO stat
NB safe in pregnancy
