STIs- path guide Flashcards
Which STIs cause discharge?
- chlamydia
- gonorrhoea
- TV
- candida
- BV
Which STIs cause ulceration?
- Syphyllis: painless
- HSV- painful
- LGV
- Chancroid
- DOnovanosis
Which STis cause rashes, lumps, growths?
Genital warts: HPV
Molluscum contagiosum
Scabies
Pubic lice
Description of neisseria gonorrhoeae
obligate intracellular gram negative diplococcus
WHat is the most common STI in europe?
Gonococcal urethrtitis
Uncomplicated gonococcal infection in men
- gonococcal urethritis
- post-gonococcal urethritis - happens following treatment. prevented by concomitant treatment with a tetracylcine
- rectal proctitis - mainly in MSM
Uncomplicated gonococcal infection in women
mucopurluent cervicitis
- erythema and oedema
- urethra (baginal leakage)
what type of discharge do you get in gonoccoal infection?
mucopurulent
Examples of complicated gonoccocal infection in men and women
Men: prostatitis
Women: PID (salpingitis) - i.e. ascending infection
What can gonorrhoea lead to in baby if left untreated in mother?
neonatal conjunctivitis
Diagnosis of gonorrhoea
*can culture but doesn’t grow very easily*
hence you do NAAT from genital swabs/urine sample
Treatment of gonorrhoea
SINGLE DOSE IM ceftriaxone
Description of chlamydia trachomatis
Obligate intracellular gram -ve pathogen
How do you culture chlamydia?
Cannot be cultured on agar
Symptoms of chlamydia
Often asymptomatic
If it does cause symptoms then these would include:
Classification of chalmydia
Classification:
o Serovars A, B, C: trachoma (infection of the eyes which can cause blindness)
o Serovars D-K: genital chlamydia, ophthalmia neonatorum
- serovars L1, L2, l3: LGV
Diagnosis of chlamydia
Diagnosis: NAAT (nucleic acid amplification tests) from genital swabs or urine test
**can’t culture on agar**
Treatment of chlamydia
azithromycin stat (1mg) OR doxycycline 100mg 7 days (BD)
**learn the doses**
(Gynae- doxycycline first line, second line is azithromycin stat)
Complications of chalmydia infection
PID à tubal factor infertility, ectopic pregnancy, chronic pelvic pain o Epididymitis o Reiter’s syndrome o Adult conjunctivitis, ophthalmia neonatorum
What causes LGV?
Lymphatic infection with Chlamydia trachomatis: serovars L1, L2 and L3
• Endemic in parts of developing world. More recently MSM in developed world
Sx of LGV
Early LGV (1° stage): 3-12 days, painless genital ulcer, proctitis, balanitis,
cervicitis
o Early LGV (2° stage): 2wks – 6 months, painful inguinal buboes, fever,
malaise
§ Rarely: hepatitis, meningo-encephalisis, pneumonitis
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o Late LGV: inguinal lymphadenopathy, genital elephantiasis, genital and
perianal ulcers / abscesses, frozen pelvis
o Current LGV outbreak: rectal symptoms / proctitis (pain, tenesmus, bleeding)
Treatment of LGV
doxycycline 100mg BD for 3wk
What cuases syphyllis?
Treponema pallidum
Description of treponema pallidum
Obligate gram-negative spirochaete
Stages of syphllis
PRIMARY: painless ulcer (chancre)
SECONDARY: systemic, soles (palms and soles)
TERTIARY: three diff characteristic syndromes (gummatous, cardiac, neuro)
Argyl roberston pupil:accommodates but doesn’t react to light
Microscopy findings of syphlis
treponemes seen on dark ground microscopy
Blood tests for syphyllis
**need to do both non-treponemal and treponemal for diagnosis because non-treponemal, even tho less specific will show you if you currently have the infection, whereas trepnonemal, while more specific, will stay positive for years even after you’ve cleared the infection **
Treatment of syphlis
What causes chancroid?
Haemophilus ducreyi
What type of organism is Haemophilus ducreyi?
. Gram -ve coccobacillus (like Hib)
Which agar does haemophilus ducreyi grow in?
chocolate agar
What type of ulcers does chancroid cause?
painful ulcers
What causes donovanosis?
Klebsiella granulomati
WHat type of bacteria is klebsiella granulomatosis?
Gram negative bacillus
Stain for donovanosis
Diagnosis: Giemsa stain of biopsy or tissue crush. Donovan bodies
What type of uclers does donovanosis cause?
Large beefy red ulcers
Treatment of donovanosis
Azithromycin
What is trichomonas vaginalis?
Flagellated protozoan
i.e. not a bacterium****
CLassic symptoms of trichomonas vaginalis
- *Men:** usually asymptomatic, sometimes urethritis
- *Females:** discharge, strawberry cervix
Treatment of trichomonas
metronidazole
What is bacterial vaginosis?
Abnormal vaginal flora, polymicrobial, ↓lactobacilli.
• Discharge, odour
• Sexually associated, not transmitted. Associated with hygiene practices (soaps)
• Diagnosis: microscopy of gram stain, raised pH, whiff test, clue cells
• Treatment: lifestyle - just use water for washing (no soaps). Metronidazole PO/topical
Candidasis
Usually Candida albicans, yeast
• Thick white discharge (“cottage cheese”), itching, soreness, redness
• Vulvovaginitis in women, balanitis in men
• Not sexually transmitted; can be part of normal flora
• Associated with immunodeficiency (incl. pregnancy, DM), hygiene practices (soaps)
• Treatment: PO / topical antifungals, e.g. clotrimazole or fluconazole
What type of virus is molluscum contagiosum?
pox virus - dsDNA
Description of mollsucum contagiosum
Small papules with central punctum
How is molluscum contagiosum spread in children vs adults?
Children: skin to skin contact
Adults: sexually transmitted
Treatment of molluscum
usually don’t need therapy
can use cryptherapy if persistent/extensive
Which forms of HPV cause genital warts?
HPV6 and HPV 11
**not associated with
Treatment of genital warts
Home treatment – Podophyllotoxin solution or cream. Not for pregnant women • Clinic treatment – Cryotherapy. 2nd line – Imiquimod
