Overview
Pelvic inflammatory disease (PID) describes inflammation of the upper female genital tract and its supporting tissues due to an ascending infection from the vagina and endocervix leading to one or more of the following:
- Endometritis – inflammation of the uterus
- Salpingitis – inflammation of the fallopian tubes
- Oophoritis – inflammation of one/both ovaries
- Parametritis – inflammation of the supportive ligaments and pelvic floor connective tissue
- Pelvic peritonitis – inflammation of the peritoneum
- Tubo-ovarian abscess – caused by an infection of the adnexae
Inflammation can lead to functional impairment of these structures and infertility.
Causes
PID is commonly, but not only, caused by sexually transmitted infections (STI) and mixed infections are common. Chlamydia trachomatis is the most common cause. Other causes include Neisseria gonorrhoea and Mycoplasma genitalium.
Pathogen-negative PID is also common.
Epidemiology
- In 2011, the overall rate of definite/probably PID diagnosis in people aged 15-44 years was 176 per 100,000 per year
- Diagnosis rates were highest in people aged 20-25 years
Risk Factors
- <25 years old
- Not using barrier contraception
- Multiple sexual partners
- Recent new sexual partner
- Previous history of PID
- Recent procedure to the uterus/cervix (e.g. termination of pregnancy, intrauterine device insertion – particularly in people with pre-existing STI infection, hysteroscopy etc.)
Presentation
People tend to present within 1 week of menses, which is thought to increase the ascent of vaginal organisms. Features include:
- Lower abdominal pain
- Abnormal vaginal discharge
- Abnormal vaginal bleeding (e.g. post-coital, intermenstrual bleeding)
- Fever
- Dyspareunia
- Cervical excitation and/or tenderness of the uterus and adnexae
- Features of pelvic peritonitis – including lower quadrant rebound tenderness
In some people, it may cause no significant symptoms except infertility and the presence of an STI in the upper genital tract.
Investigations
Overview
Some investigations (depending on availability) include:
- Pregnancy testing – to exclude an ectopic pregnancy
- High vaginal swab to screen for Chlamydia and gonorrhoea – a negative result does not rule out PID
- Microscopy of endocervical/vaginal pus cells – absent pus cells make PID less likely
Other tests to consider include:
- Full blood count (FBC) – may show leukocytosis
- Erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) – may be elevated
- STI screening – HIV, hepatitis B and C, and syphilis
Management
Overview
- 1st-line: oral ofloxacin + oral metronidazole or IM ceftriaxone + oral metronidazole + oral doxycycline
- Consider intrauterine device removal. In mild cases of PID, this may be left in.
Complications
Chronic pelvic pain – likely due to inflammation causing scarring and adhesions.
Infertility – due to inflammation of the pelvic organs, scarring, and adhesions, which can obstruct the fallopian tubes and/or damage ciliated epithelial cells, impairing ovum transport. The risk can be as high as 20% after a single episode.
Ectopic pregnancy – due to inflammation, scarring, and adhesions.
Pelvic peritonitis and sepsis – this can be potentially life-threatening.
Tubo-ovarian abscess – presents with severe pelvic pain, fever, and constitutional symptoms. This may rupture and cause sepsis.
Perihepatitis (Fitz-Hugh-Curtis syndrome) – causative organisms can ascend from the vagina into the endometrium, into the Fallopian tubes, and the peritoneal cavity, causing inflammation of the hepatic capsule, resulting in right upper quadrant pain.
Prognosis
- Early and complete treatment is associated with a relatively high cure rate (~80-100%)
