Infection involving the uterus, uterine tubes, parametria or overlying peritoneum
Ideally the diagnosis is made following the result of genital swab cultures, or following diagnostic laparoscopy. Most cases however are diagnosed on clinical grounds with inherent risk of misdiagnosis. The true incidence is unknown, but any estimation based on presentation to gynaecologist is likely to be an underestimate because of the number of cases of atypical or silent PID.
Why is PID important?
Male genital disease
Acute PID can be a systemic illness, with fever, rigors & septicaemia. Long term pain, dysmenorrhoea and/or dyspareunia occurs in about 15-20% of patients, not infrequently resulting in hysterectomy at a young age. Chronic pain following an acute attack is common, lasting up to 6 months. This shouldnt be confused with chronic PID, and when this is excluded, reassurance and analgesia is all that is required.
It has been estimated that about 1/4 of patients with PID will have further episodes - screen and treat her partner(s)!! 70% of women in infertility clinics with tubal factor disease have serological evidence of anti-chlamydial antibodies, even though 50% give no history of previous PID.
Studies have shown that with laparoscopically diagnosed PID there is an average infertility rate of 20%. Following one episode it is 13%, 2 episodes 36% and after 3 episodes 75%. The severity also seems to be important: afer a mild episode permanent tubal damage may follow in 1%, in a moderate episode 6% and following a severe episode of PID, as many as 21% of women may have tubal comprimise.
Ectopic pregnancy is more common following PID with the ratio of ectopics to intrauterine pregnancies 1:24 compared to 1:147 in the general population. Consequences for male include urethritis, epidydimo-orchitis and gonococcal urethral fistulae.
Gram negative bacilli - e.g. E. coli
Gram positive cocci - e.g. Groups B&D Streptococci
Anaerobes - e.g. Bacteroides species
Chlamydia is the commonest sexually transmitted organism in the UK. The role of mycoplasma homonis in PID is not yet elucidated, though it is thought to be an opportunistic secondary pathogen rather than causative agent of acute PID. Actinomyces is a strictly anaerobic, branching bacillus found in association with IUCDs. It is a commensal of the mouth and appendix. Its route of introduction into genital tract is unknown & thought to be either via the bowel or transmitted during oro-genital sex.
That PID is predominantly caused by sexually transmitted organisms is well established (though frequently played down to patients until positive cultures are obtained). It occurs rarely in virgins and is much more likely in those who have multiple sexual partners. Its incidence peaks in women aged 15-25 years, most likely reflecting the sexual activities of this age group. Remember to take a sexual history - there may be more than one partner implicated.
The tails of intrauterine contraceptive devices may aid entrance of organisms to the upper genital tract. The relative risk of PID for IUCD users is 3x that of non-users and for nulliparous women is increased to a 7-fold increase. One study showed that most of the increase in risk is in the first 4 months of use, with no increase in risk thereafter. This data refutes the belief that they should be changed after 3 years of use because of increased risk of infection after this time.
Clinical features: Acute PID
Offensive vaginal discharge
Malaise, vomiting, fever
Irregular vaginal bleeding
Lower abdominal tenderness
Bilateral adnexal tenderness, cervical excitation
A study including 1000 laparoscopies has demonstrated various clinical indicators to be poorly sensitive & specific, the diagnosis being correct in only 46-71% of cases.
Inspection: Vulva, LN
Speculum: vagina, cervix
Uterine size, av/rv, axial/deviated laterally, mobility, tenderness, cervical excitation
Adnexa: tenderness, masses
When carrying out a gynaecological examination, it is important to think methodically about what you are doing.
Inspection: ?lymph nodes (eg. genital herpes), pubic lice, vulval warts or ulcers (herpes/syphilis)
Speculum: visualisation of vagina for lesions & presence of discharge. Swabs should be taken including endocervical for chlamydia/gonorrhoea and vaginal for trichomonas.
Bimanual: The aim is to be able to document your findings clearly covering the points above so that a collegue reviewing your notes can build up a 3D picture of your findings.
Clinical features: Chronic PID
General malaise & fatigue
Chronic lower abdominal pain
Intermittent offensive vaginal discharge
Generalised lower abdominal tenderness
Bulky, tender uterus
Sensitive pregnancy test
Full blood count
A pregnancy test excludes pregnancy related causes of acute pelvic pain. ESR & CRP are poorly specific or sensitive in diagnosis of PID, being raised in the other differential diagnoses, including ectopic & torsion of ovarian cysts. Triple swabs are taken, as above, urethral to improve chlamydia detection rates & urethral, pharyngeal and rectal if gonococcus suspected.
The Royal College of Radiologists has recommend that USS be a routine investigation in PID, and may be useful when a tubo-ovarian mass is suspected, and helps exclude ovarian cyst torsion. The use of laparoscopy in PID has increased much in recent years, and early laparoscopy with standardised clinical criteria reduces diagnostic uncertainty, allows assessment of the severity of the disease and a better prognosis of subsequent fertility.
Oral vs parenteral
Inpatient vs outpatient management
Patients who are systemically unwell, vomiting or who have more severe pelvic signs will require admission and intravenous antibiotics, otherwise outpatient management may be appropriate.
Ampicillin 500mg qid IV
Metronidazole 1g bd PR
Doxycycline 100mg bd PO
Doxycycline 100mg bd PO x14 days
Metronidazole 400mg bd PO x10 days
There are many antibiotic regimes suitable for the treatment of pelvic inflammatory disease and local guidelines should be formed in collaboration with microbiologists. One suitable example is shown above. In penicillin sensitive patients, a 3rd generation cephalosporin may be chosen. Ciprofloxacin 250 mg stat is added when there is a high suspicion of gonococcus (increasing penicillin-resistance).
In pregnancy, Augmentin or erythromycin are proven choices, though are less likely to cure in one course, so ensure a test of cure is performed.
Surgery has a limited place in chronic PID with tubo-ovarian mass - the aim is conservative with drainage of any collection and placement of a drain, but radical surgery is not unusual and varies from simple salpingectomy to hysterectomy.
When prescribing TTOs, remember to warn about the metronidazole/alcohol interaction and advise avoidance of sexual intercourse.
14 days in gynaecology clinic
Test of cure
Contact tracing via GUM
If possible try and see the patient yourself and ensure male partners have been screened and treated.