Sexually-Transmitted Infections (STI)

Chlamydia

N.B. Most common STI in the UK.

This is caused by Chlamydia trachomatis.

It presents with:

• Women - asympomatic, vaginal discharge, dysuria, IMB, PCB

• Men - urethral discharge, dysuria

It's investigated with a NAAT on a Vulvovaginal/Endocervical swab or Urethral swab.

It's managed with PO Doxycycline 100mg BD for 7 days.

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

Complications include:

• PID - Can lead to scarring and infertility

• Epididymitis - Can lead to infertility if left untreated

Gonorrhoea

This is caused by Neisseria gonorrhoeae.

It presents with discharge and dysuria in women and men.

It's investigated with a MC&S and NAAT on Vulvovaginal swab or First-pass urine/Urethral swab.

It's managed with IM Ceftriaxone 500mg-1g.

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

Complications include:

• PID - Can lead to scarring and infertility

• Epididymitis - Can lead to infertility if left untreated

Syphilis

This is caused by Treponema pallidum.

It can present as:

• Primary syphilis - Chancre, which is a painless, solitary ulcer that usually heals within 3-8 weeks

• Secondary syphilis - Widespread, maculopapular symmetrical rash on the palms, legs, soles and face

• Tertiary syphilis

  • Neurosyphilis - headache, altered behaviour, dementia, tabes dorsalis (inflammation of spinal dorsal columns), Paralysis, Sensory impairment

  • Aortitis

There are a few differentials of a genital ulcer to remember:

It's investigated by:

• Swab of chancre

• Serology - check for Ab's

It's managed with a one-off dose of IM Benzathine benzylpenicillin.

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

Trichomoniasis Vaginalis/TV

N.B. This is a  flagellated protozoa (aka parasite).

It presents with:

• Women - Vaginal discharge (yellow, frothy), Dysuria, Vulval irritation, Dyspareunia, Strawberry cervix O/E

• Men - Urethral discharge, Dysuria, Urethritis

It's investigated with a MC&S and NAAT on Posterior fornix swab or First-pass urine/Urethral swab.

It's managed with Metronidazole 400mg BDS for 5-7 days.

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

Herpes Simplex Virus/HSV

Types:

• HSV-1 - Usual cause of oral herpes, and now the most common cause of genital herpes in the UK

• HSV-2 - Less common, but more likely to cause recurrent anogenital symptoms

After primary infection, the virus typically moves to become latent in local sensory ganglia, before reactivating to cause symptomatic lesions. These recurrent episodes are usually less severe.

It presents with:

• Multiple, painful ulcers - typically crust over and heal

• Dysuria

• Vaginal/urethral discharge

It's investigated with a NAAT on ulcer swab.

It's managed with:

• Antivirals

• Analgesia - Topical lidocaine for symptomatic relief

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

A key complication here is HSV Encephalitis, which presents with the 3 F’s - Fever, Fits, Funny behaviour. This typically affects the Temporal and Inferior frontal lobes of the brain.

Genital Warts

This is caused by HPV (esp. strains 6 and 11).

It presents with painless, cauliflower-like lumps which are either keratinised or non-keratinised and found on areas that are traumatised during sex.

It's diagnosed clinically by the presence of characteristic warts/lesions.

It's managed with:

• Reassurance - tends to go on its own, so any management is for cosmetic reasons

• Cryotherapy, creams, surgery

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

Pelvic Inflammatory Disease/PID

This is most commonly caused by Gonorrhoea and Chlamydia.

It presents with:

• Symptoms - Lower abdominal pain, Discharge, PCB

• Signs - Fever, Adnexal tenderness, Cervical motion tenderness

If the patient is having RUQ pain, suspect Fitz-Hugh-Curtis syndrome, in which there's inflammation of the membrane between the liver and peritoneum.

It's investigated with:

• Pelvic examination

• Pregnancy test

• Swabs for gonorrhoea and chlamydia

• TVUS

It's managed with Ceftriaxone IM + Doxycline (for chlamydia) + Metronidazole (for gonorrhoea).

N.B. Patient has to notify their partner and abstain from sex until treatment is completed.

Complications include:

• Chronic pelvic pain

• Infertility

• Ectopic pregnancy - due to scarring of fallopians