STIs

Question 1

What STIs cause itch as their main symptom?

Answer 1

Scabies
Pubic lice
Trichomonas
Candida (not STI)

Question 2

Does HSV recur?

Answer 2

Yes
HSVI 50% chance of recurrence evry 12-18months
HSVII 3-4 times a year

Question 3

Main symptoms & signs of HSV

Answer 3

Burning sensation, tenderness, urethritis, dysuria

Erythema-> vesicles-> ulcers and pustiles-> scabbing

Question 4

Diagnosis of HSV?

Answer 4

HSV NAATS from base of lesion

From clinical appearance

Question 5

Treatment of HSV

Answer 5

Aciclovir 2-400mg 5DS PO 10days
Saline bathing, instillagel
Recurrent-> prophylactic aciclovir

Question 6

Complications of HSV

Answer 6

Viral meningitis
Neonatal infection
-> encephalitis (6% mortality, 70% morbidity)
->dissemination (30% mortality)

Question 7

What can be done to limit vertical transmission of HSV?

Answer 7

If 1st episode HSV in 3rd trimester, PO aciclovir 400mg TDS until delivery

Question 8

Describe HPV

Answer 8

Human papilloma virus
30 types
16&18 oncogenic
6&11 genital warts
80% people are exposed, usually a 6 month infection

Question 9

How can you describe warts?

Answer 9

Keratinised/non keratinised
Mucosal
Internal/satellite

Question 10

Treatment of genital warts

Answer 10

• Podophyllotoxin 0.15% cream causing local tissue necrosis, only for non-keratinised warts, teratogenic
• Imiquimod 5% cream, stimulates immune system, all types of wart, not in pregnancy
• Cryotherapy, liquid nitrogen freezing
• Excision

Question 11

What is the HPV vaccine?

Answer 11

Now quadrivalent, oldest females are now 26. Heterosexual men are benefiting from herd immunity. However HIV+ve homosexual men have no coverage and are at risk of anal cancer.

Question 12

What are molluscum?

Answer 12

Molluscum contagiosum
• Benign epidermal eruptions
• Pox virus
• Children (face, neck, trunk, limbs)
• Sexual infection (young adults, genitals, pubic region, upper thighs, buttocks)
• Severe ‘giant’ in HIV+ve
• Can become secondarily infected with staph
• Regress spontaneously in months
• Warn about autoinoculation, wart creams are not licensed for MC

Question 13

What is N. gonorrhoea? Symptoms?

Answer 13

• Gram negative diplococcus, intracellular
• Infects mucous membranes
• Causes dysuria, discharge (urethral and vaginal), proctitis, pharyngitis and conjunctivitis
• Can ascend to cause PID / epididymitis
• Can disseminate (Fever, rash, arthritis)

Question 14

What can N. gonorrhoea do in pregnancy?

Answer 14

IUGR, prematurity, PROM in pregnancy

Question 15

How is N. gonorrhoea diagnosed?

Answer 15

NAAT, culture, microscopy if urethritis (shows >5 pus cells with segmented nuclei and diplococci)

Question 16

Treatment of Gonorrhoea?

Answer 16

Check local guidelines due to resistance (ceftriaxone + azithromycin)
No sex for a week after treatment
Test of cure

Question 17

What is chlamydia trachomatis?

Answer 17

• Very common (5% of population)
• Serovars A-L (D-L genital)
• Very small, intracellular bacteria, cannot be seen by light microscopy
• Incubation 7-21 days
• Causes dysuria, discharge (urethral and vaginal), proctitis, pharyngitis and conjunctivitis but majority are asymptomatic
• Can cause PID, infertility and ectopic pregnancy, miscarriage, prematurity

Question 18

What is PID?

Answer 18

Pelvic inflammatory disease
Chlamydia causes PID in 10-30% if untreated (fever, pelvic pain, adnexal tenderness, cervical excitation)
1 episode of PID-> 21% tubal infertility rate, 2 episodes 75% tubal infertility

Question 19

Chlamydia in pregnancy?

Answer 19

50% vertical transmission if untreated in pregnancy (neonatal conjunctivitis and pneumonitis, amnionitis)

Question 20

Diagnosis of chlamydia?

Answer 20

Nucleic acid amplification test (NAAT) from anal swabs/self taken vulvovaginal swabs or first catch urine

Question 21

Treatment of chlamydia?

Answer 21

DOXYCYCLINE 100mg BD 7days or ERYTHROMICIN BD 14days + test of cure in pregnancy

Question 22

Symptoms of mycoplasma genitalium?

Answer 22

Dysuria , Discharge, upper genital tract infection, proctitis
Similar problems to chlamydia
Hard to find so use NAATS

Question 23

What is syphilis?

Answer 23

• Caused by Treponema pallidum
• Spirochete bacterium

1º:Painless chancre, regional lymphadenopathy (9-90 days)

2º: Mucosal lesions, rash, lymphadenopathy, meningitis, iritis, palms and soles (3 months)

Latent: Asymptommatic

3º: CVS: aortic aneurysm, aortic regurg, gummatous syphilis. Neuro: tabes dorsalis, stroke, general paresis, dementia

Question 24

Risk populations for syphilis?

Answer 24

Homosexual men, HIV+ve, sexual contact from endemic area, tissue donation

Question 25

Diagnosis and treatment of syphilis

Answer 25

PCR/serology, dark field microscopy | IM benzathine penicillin

Question 26

What is Trichomonas vaginalis?

Answer 26

- Found in urethra/vagina - Flagellated protozoan parasite - Dysuria/urinary frequency - Frothy yellow discharge - Offensive odour

Question 27

Treatment of trichomonas vaginalis?

Answer 27

Metronidazole 400mg BD 5-7days | Contact trace partners back 4/52 & treat them regardless of test results

Question 28

What causes chancroid?

Answer 28

Haemophilus ducreyi

Question 29

What is LGV?

Answer 29

* Lymphogranulum venereum * Chlamydia trachomatis L1, 2, 3 * Causes inflamed lymphatics, scarring and tightening * Has been mistaken for ‘apple coring’ colorectal cancer

Question 30

What is donavanosis?

Answer 30

* Papau New Guinea | * Klebsiella granulomatosis

Question 31

Diagnosis of trichomonas vaginalis?

Answer 31

* Wet film microscopy:40-60% sensitivity * Point of care test (POCT): 80-94% sensitivity, ready in 15-30mins, risk of false positive * Culture: can also use in men * NAAT: 88-97% sensitivity, can also use in men, new ‘gold standard’ * Cervical cytology – need to confirm diagnosis

Question 32

Trichomonas vaginalis and pregnancy?

Answer 32

Associated with preterm delivery, low birth weight and post-partum sepsis Vertical transmission in 5%

Question 33

Describe pubic lice

Answer 33

Large pincers to cling onto thick body hair 3 stages: Nit (white oval egg attached to hair base, 10-50 laid per louse) Nymph (Hatches in 7 days, migrates to hair base) The adult (1-2mm grey/brown, 3 pairs of legs, can move 10cm a day) If nits are above hair base, this shows how long they've been there

Question 34

Public lice are commoner when?

Answer 34

* Commoner in the cooler months * Commoner in MSM * Needs skin-skin contact (or occasionally sharing underwear)

Question 35

Symptoms of pubic lice and sites

Answer 35

* Thighs, perineum, trunk, abdomen, axillary hair * Eyebrows, eyelashes (rarely scalp) Intense irritation, movement noticed Blue macules, black spots, lice and nits

Question 36

Treatment of pubic lice

Answer 36

* Malathion 0.5% * Permethrin 1% (pregnancy) * Lotions better than shampoos * Body hair treated and left for 12 hrs * New linin * Repeat after 1 week * Full STI screen

Question 37

Describe scabies

Answer 37

* Parasitic mite * Life span 4-6 weeks * Female burrows into the skin, lays its eggs (1-3/day) * Feeds on lymph and lysed tissue * Larvae hatch and mature over 10 days * 8 legs * Can’t see with the naked eye * Spread with skin to skin contact, frequently sexually transmission * Sporadic outbreaks in families/institutions

Question 38

Symptoms of scabies

Answer 38

* Hypersensitivity reaction * Pruritus (worse at night) * Symmetrical eczematous looking lesions (hands, genital, elbow, nipple area * Burrows (fine channels) * Indurated nodules * May be secondary bacterial infection

Question 39

Management of scabies?

Answer 39

* Permethrin 5% * Malathion 0.5% * Apply from neck down and leave for 12hrs * Repeat a week later * Irritation may last several week after treatment * Treat sexual partner and household contacts

Question 40

Describe Norwegian scabies

Answer 40

* Same mite * Found in people that are immunocompromised and elderly * Highly contagious * Thousands of mites * Extensive crusted lesions with hyperkeratotic scales * Less pruritic * Treatment is isolation and repeat applications * Oral Ivermectin if topical treatments don’t work