Obs & gynae clinic - pelvic inflammatory disease

The case

A 25-year-old nulliparous woman presents with lower abdominal discomfort and vaginal discharge of seven days duration. She has recently changed partners and uses condoms on an irregular basis. Her last menstrual period was 20 days ago. She has had vaginal spotting for the last four days. On examination, she has a pulse of 84 bpm and temperature 37.8 C. Her lower abdomen is tender all over with mild guarding. The cervix is clinically normal in appearance, with an increased amount of vaginal discharge that is not obviously purulent. She is mildly tender on vaginal examination and on cervical excitation. No pelvic masses are noted.

Pelvic inflammatory disease (PID)

PID refers to inflammation of the uterine cavity, fallopian tubes, ovaries or pelvic peritoneum, as a result of infection ascending from the endocervix. Common specific pathogens include Chlamydia trachomatis and Neisseria gonorrhoeae, and an increasing role is suspected for Mycoplasma genitalium. Often multiple anaerobic and aerobic organisms are cultured from the genital tracts of women with PID and sometimes no specific pathogens may be identified.

Features

The clinical features of PID can vary from an acute and severe presentation to a more chronic development of lower abdominal pain and backache. In some women with chronic PID there may be recurrent episodes of acute exacerbation on a background of low-grade abdominal discomfort. The clinical presentation of PID is not specific and the positive predictive value of common signs and symptoms is around 65-90%. The following features should give rise to a suspicion of PID:¹

Bilateral lower abdominal tenderness (sometimes radiating to the legs)
Abnormal vaginal or cervical discharge
Fever (greater than 38°C)
Abnormal vaginal bleeding (intermenstrual, postcoital or ‘breakthrough’)
Deep dyspareunia
Cervical motion tenderness on bimanual vaginal examination
Adnexal tenderness on bimanual vaginal examination (with or without a palpable mass).

Diagnosis

A low threshold for empirical treatment is recommended owing to the non-specific nature of clinical features in women with PID. Laparoscopy may be beneficial in confirming the diagnosis and to rule out other causes, but is not indicated in the majority of cases seen in primary care.

Women with PID due to gonorrohoea tend to have the most acute presentation, while those with Chlamydia or mycoplasma infections present less clinically severe cases and take longer to present. In a recent study, patients with PID due to Chlamydia presented for care on average 12.3 days after the onset of symptoms, while women with gonorrhoeal PID presented an average of 4.6 days after the start of their symptoms.² Infections may be more severe in women with HIV.

Differential diagnoses

The following conditions may mimic the presentation of acute PID:

ectopic pregnancy
ovarian cyst accident, i.e. torsion or rupture
appendicitis
uti
endometriosis

Clinical history, examination, pelvic ultrasound, MRI and CT scans may help identify these conditions. In case of persistent diagnostic uncertainty, laparoscopy may be indicated. However, even laparoscopy may not be conclusive, as it does not identify endometritis.

Conditions which may present in a similar way to chronic PID include the following:

endometriosis
irritable bowel syndrome
inflammatory bowel disease
chronic pelvic pain of unknown cause

Clinical assessment and pelvic imaging (as above) may help clarify the diagnosis. Laparoscopy is often required to make the distinction between chronic PID and endometriosis. The typical laparoscopic appearances include pelvic and peri-hepatic adhesions and damaged, occluded fallopian tubes. There may be tubo-ovarian abscesses and fluid collections within pelvic peritoneal adhesions mimicking ovarian cysts.

Management

Women with suspected PID should be tested for gonococcal and chlamydia infection.

Endocervical swabs can be tested for gonorrhoea by culture or nucleic-acid amplification test (NAAT) – culture has the advantage of establishing antibiotic sensitivity to guide treatment.

If it is not possible to take a swab prior to starting antibiotic treatment, there may still be value in taking a swab at the earliest opportunity in case there is failure to respond to first-line antibiotics. A urine pregnancy test is recommended.

Mild or moderate PID without a tubo-ovarian abscess can be managed on an outpatient basis in primary care.

Antibiotics should be started as soon as the diagnosis is suspected to reduce the risk of long-term sequelae and recommended regimes include

oral ofloxacin 400 mg twice daily plus metronidazole 400 mg twice daily for 14 days

intramuscular ceftriaxone 500 mg single dose, followed by oral doxycycline 100 mg twice daily plus metronidazole 400 mg twice daily for 14 days.

Ofloxacin should not be used where gonorrhoea is suspected – doxycycline should be used instead. Metronidazole may be discontinued if poorly tolerated due to nausea.

Women with HIV infection should be managed with the same antibiotic regime, unless severely affected (see below).

Evidence is scant concerning the appropriate regimes for managing PID in a woman who is pregnant. However, the associated increased maternal and fetal morbidity should lead to hospital-based care using parenteral antibiotics. The precise regime should be agreed with local microbiology experts. In most cases, the risk of teratogenicity is exceeded by the risk of the disease and antibiotic therapy should be used even if the patient is, or could be, pregnant.

The patient should be reviewed within 72 hours of starting treatment. In women with an IUD in situ, this should be removed if symptoms persist despite 72 hours of antibiotic treatment. In practice, if there is no significant improvement after 72 hours of one of the recommended antibiotic regimes (see above) referral to hospital may be indicated, particularly if the woman has moderately severe disease.

For patients with clinically severe infection, tubo-ovarian abscess, concurrent pregnancy, lack of response to outpatient antibiotics or where there is diagnostic uncertainty, hospital admission is required.

The woman’s sexual contacts should be traced and tested for infection through the relevant sexual health service. The patient and her partners should be advised not to have sexual intercourse until all treatment is complete. The patient should be advised about potential effects on her future fertility and risk of ectopic pregnancy. Future contraceptive options for a woman who has had PID should take into account her individual risk profile. If she wants an IUD, Mirena is an appropriate option.

Dr Raj Mathur is a consultant gynaecologist at Cambridge University Hospitals NHS Foundation Trust

References