Pelvic inflammatory disease

Pelvic inflammatory disease (PID) is an acute, ascending polymicrobial infection of the upper female genital tract. It most commonly associated with STIs such as chlamydia trachomatis, Neisseria gonorrhoeae or Mycoplasma genitalium. It is not only STIs, however, as vaginal flora may also disseminate into PID.

PID encompasses a spectrum of inflammatory disorders of the upper female genital tract. This includes any combination of:

PID is concerning as it can distort the anatomy of the reproductive organs and thus increasing the likelihood of infertility and ectopic pregnancy. It can also lead to adhesion formation between the liver and peritoneum leading to perihepatitis (also known as Fitz-Hugh-Curtis syndrome).

Pathophysiology

Pathogens such as Neisseria and Chlamydia are primary pathogens which damage the endocervix. This allows secondary pathogens which are endogenous vaginal and cervical microflora to invade into the upper genital tract (for example, Gardnerella vaginalis). This spread may also occur when inserting instruments into the cervix to gain access to the uterus (as seen when placing an intrauterine device, termination of pregnancy, dilation and curettage procedures). Sometimes PID can also occur secondary to diseases such as a ruptured appendix, gastroenteritis and bacterial vaginosis.

These microbes ultimately damage and distort the normal anatomy of the pelvis and reproductive organs. It leads to tubal damage, adhesions, abscess which can ultimately lead to chronic pelvic pain, infertility and ectopic pregnancies.

⚠️ Risk factors

😷 Presentation

In many women, PID may progress and cause significant scarring to the anatomy while the woman remains asymptomatic.

Symptoms that are highly indicative of PID include:

• Lower abdominal pain
• Unexplained vaginal discharge
• Fever
• Nausea and vomiting - especially when the pain is severe.

We may also consider PID when there is irregular vaginal bleeding, dyspareunia or dysuria that is unexplained.

Let’s take a look at some of the symptoms that may present and classify them based on the region of the genital tract affected:

• Cervicitis
1. Vaginal/cervical discharge - it may be purulent or mucopurulent.
2. Post-coital bleeding - due to cervical friability.
3. Dyspareunia
4. Cervical motion tenderness (cervical excitation or Chandelier sign) - indicative of peritoneal spread and occurs in the later stages of the disease.
• Salpingitis
1. Bilateral abdominal pain
2. Adnexal tenderness
• Endometritis
1. Uterine tenderness
2. Irregular menstruation and irregular vaginal bleeding
3. Dysuria

🔍 Investigations

PID investigations should include the following:

• History, speculum and bimanual examination
• FBC, CRP, ESR
• Pregnancy test
• Nucleic acid amplification test (NAAT) - using cervical/endocervical specimens to test for N. gonorrhoeae, and C. trachomatis. If mycoplasma genitalium testing is available it should also be done. Negative results do not exclude a diagnosis of PID, however.
• Wet-mount vaginal smear - should show polymorphonuclear cells (such as neutrophils, eosinophils, basophils). If they are not present then PID is unlikely but their presence is not sensitive, so it is good at ruling the disease out but not at ruling it in.
• Urinalysis + urine MC&S - to exclude UTI.

📷

Imaging:

1. Transvaginal ultrasound - can also be used to confirm the diagnosis when uncertain.
2. Laparoscopy - this is the gold-standard diagnostic method but is not done routinely due to its invasive nature and associated risk.

🧰 Management

The objective with treatment of PID is to eradicate the causative agent in an attempt to avoid long-term complications such as infertility, tubal scarring, ectopic pregnancy.

Some general advice is to rest, take analgesics such as paracetamol or NSAIDS, and to avoid unprotected sex until the patient and partner(s) have completed the treatment and follow-up (otherwise emphasise the importance of barrier contraception).

Patients should be reviewed at 72 hours. Failure to improve at this stage suggests that further investigations need to be done or parenteral/surgical therapy should be conducted. Patients should also be have a transfer of care (TOC) to the local sexual health service or primary care if they have gonorrhoea, chlamydia, mycoplasma genitalium, persisting symptoms, recurrent infection or poor compliance.

🚨 Complications

• Fitz-Hugh Curtis syndrome- this is perihepatitis (inflammation of the hepatic capsule) that leads to adhesions between the hepatic capsule and peritoneum presenting with RUQ pain that may refer to the right shoulder. It mimics acute cholecystitis. It can become chronic in which there are phases of exacerbations with intermittent remissive periods.
• Tubo-ovarian abscess - collection of pus in the adnexa. It occurs in about 15% of women with salpingitis. It is more likely if treatment is late or incomplete. Pain, fever and peritoneal signs are present and severe usually. An adnexal mass may be palpable on examination but due to the tenderness on examination with PID, this may limit the examination. A ruptured abscess can subsequently lead to sepsis and septic shock.
• Hydrosalpinx - a fimbrial obstruction leads to tubal distension with serous fluid filling. It is most commonly asymptomatic but may lead to pelvic pressure, chronic pelvic pain, dyspareunia, and/or infertility.
• Scarring
• Adhesions
• Infertility
• Ectopic pregnancy