Pelvic inflammatory disease (PID) is usually the result of infection ascending from the endocervix causing endometritis, salpingitis, parametritis, oophoritis, tubo-ovarian abcess and/or pelvic peritonitis.

Neisseria gonorrhoeae and Chlamydia trachomatis account for a quarter of UK cases.

Gardnerella vaginalis, anaerobes (Prevotella, Atopobium and Leptotrichia) and other organisms commonly found in the vagina likely play a role.

Mycoplasma genitalium has been associated with upper genital tract infection in women and is a very likely cause of PID.

The insertion of an intrauterine device (IUD) increases the risk of developing PID but only for 4-6 weeks after insertion. This risk is probably highest in women with pre-existing gonorrhoea or trachomatis.

Symptoms:

• lower abdominal pain, typically bilateral
• deep dyspareunia
• abnormal vaginal bleeding, including post coital, inter-menstrual and menorrhagia
• secondary dysmennorhoea
• abnormal vaginal or cervical discharge, often purulent

Signs:

• lower abdominal tenderness, usually bilateral
• adnexal tenderness
• cervical motion tenderness 
• fever (>38°C)

Diagnosis of PID and empirical antibiotic treatment should be considered and usually offered in any woman under 25 who has recent onset, bilateral lower abdominal pain associated with local tenderness on bimanual examination, in whom pregnancy has been excluded.

Complications:

Fitz-Hugh-Curtis syndrome comprises right upper quadrant pain associated with perihepatitis

Randomised controlled trial evidence for whether an intrauterine contraceptive device should be left in situ or removed in PID is limited. The decision to remove the IUD needs to be balanced against the risk of pregnancy. Hormonal emergency contraception may be appropriate for some women in this situation.

Women with HIV may have more severe symptoms but respond well to standard treatment (Grade 1B).

PID may be symptomatic or asymptomatic.

Symptoms and signs lack sensitivity and specificity (positive predictive value of a clinical diagnosis is 65-90% compared to laparoscopic diagnosis).

A positive test for gonorrhoea, chlamydia or M. gen supports the diagnosis but the absence of infection does not exclude PID. Testing for all three organisms is recommended. Local availability of M. gentesting currently varies but implementation of testing is strongly recommended to guide the choice of appropriate therapy.

Elevated ESR or C-reactive protein also supports the diagnosis but is non-specific. 

The absence of endocervical or vaginal pus cells has a good negative predictive value (95%) for a diagnosis of PID but their presence is non-specific (poor positive predictive value – 17%).

Differential diagnosis of lower abdominal pain in a young woman includes:

• Ectopic pregnancy 
• Acute appendicitis
• Endometriosis
• Ovarian cyst torsion or rupture 
• Urinary tract infection
• Functional pain 

Delaying treatment is likely to increase the risk of long-term sequelae such as ectopic pregnancy, infertility and pelvic pain. Because of this, and the lack of definitive diagnostic criteria, a low threshold for empiric treatment of PID is recommended. Broad spectrum antibiotic therapy is required to cover a wide variety of aerobic and anaerobic bacteria.  

Further Investigations:

• Pregnancy test
• Screening for sexually transmitted infections including HIV

General Advice:

Rest if severe disease (Grade 1D).

Analgesia (Grade 1D).

Intravenous therapy is recommended in more severe clinical disease (Grade 1D) e.g. pyrexia > 38⁰C, signs of tubo-ovarian abscess or pelvic peritonitis.

Avoid unprotected intercourse until patient and partner(s) have completed treatment and follow-up (Grade 1D).

Give a detailed explanation with clear and accurate written information (Grade 1D). A patient information leaflet is here

Admission for parenteral therapy, observation and possible surgical intervention should be considered in clinically severe disease, if a surgical emergency cannot be excluded, if no response to oral therapy and in those with a tubo-ovarian abscess or who are pregnant. 

All the recommended regimens are of similar efficacy.

(1) Outpatient Regimens:

• Intramuscular ceftriaxone 1000mg single dose plus
• Oral doxycycline 100mg BD for 14 days plus 
• Oral metronidazole 400mg BD for 14 days [Grade 1A]

or

• Oral ofloxacin*/*** 400mg BD for 14 days
• Oral metronidazole* 400mg BD for 14 days [Grade 1A]

or

• Oral moxifloxacin 400mg OD for 14 days [Grade 1A]**/***

*Ofloxacin and moxifloxacin should be avoided in patients who are at high risk of gonococcal PID because of increasing quinolone resistance in the UK. Quinolones are not licensed in under 18s

**Of the three recommended PID treatment regimens, moxifloxacin provides the highest microbiological activity against M. genitalium.

*** Ofloxacin, levofloxacin and moxifloxacin are effective for the treatment of C. trachomatis. Quinolones (ofloxacin, levofloxacin and moxifloxacin) can cause disabling and potentially permanent side-effects involving tendons, muscles, joints and the nervous system, and are therefore only recommended as second line therapy, except for the treatment of M. genitalium associated PID where no alternative therapy is available.

Alternative Outpatient Regimens:

• Intramuscular ceftriaxone 1000 mg immediately
• Oral azithromycin 1 g/week for 2 weeks [Grade 2B]

(2) Inpatient Regimens:

Intravenous therapy should be continued until 24 hours after clinical improvement and then switched to oral. 

• Intravenous ceftriaxone 2g daily
• Intravenous doxycycline 100mg BD (oral if tolerated)

Followed by:

• Oral doxycycline 100mg BD for 14 days
• Oral metronidazole 400mg BD for 14 days [Grade 1A]

or

• Intravenous clindamycin 900mg TID
• Intravenous gentamicin* 2mg/kg loading dose followed by 1.5mg/kg TID

Followed by:

• Oral clindamycin 450mg QID to complete 14 days OR oral doxycycline 100mg BD to complete 14 days
• Oral metronidazole 400mg BD to complete 14 days [Grade 1A]

*Gentamicin levels need to be monitored if this regimen is used.

Alternative Inpatient Regimens:

• Intravenous ofloxacin 400mg BD for 14 days
• Intravenous metronidazole 500mg TID for 14 days [Grade 1B]

or

• Intravenous ciprofloxacin 200mg BD for 14 days

or

• Intravenous (or oral) doxycycline 100mg BD for 14 days

plus

• Intravenous metronidazole 500mg TID for 14 days [Grade 1B]

Pregnancy and Breastfeeding

• PID in pregnancy is uncommon but associated with an increase in both maternal and fetal morbidity, therefore parenteral therapy is advised although none of the suggested evidence based regimens are of proven safety in this situation.
• there are insufficient data from clinical trials to recommend a specific regimen and empirical therapy with agents effective against gonorrhoea, C. trachomatis and anaerobic infections should be considered taking into account local antibiotic sensitivity patterns (e.g. i.v. ceftriaxone, i.v. erythromycin and i.v. metronidazole switching to oral therapy following clinical response and completing 2 weeks of treatment) (Grade 2D).
• use of the recommended antibiotic regimens (listed above for non-pregnant women) in very early pregnancy (prior to a pregnancy test becoming positive) is justified by the benefits of treatment of PID at any stage of pregnancy being likely to outweigh any possible risks (personal communication, UK National Teratology Information Service – 15th October 2018)

Surgical Management

Laparoscopy may help early resolution by dividing adhesions and draining pelvic abscesses but ultrasound guided aspiration of pelvic fluid collections is less invasive.

Follow Up

Review at 72 hours is recommended, particularly if moderate or severe signs (Grade 2D).

Failure to improve suggests the need for further investigation, parenteral therapy and/or surgical intervention.

Further review 2-4 weeks (Grade 1D) after therapy may be useful to ensure:

• Adequate clinical response 
• Compliance with oral antibiotics
• Screening and treatment of sexual contacts
• Awareness of the significance of PID and its sequelae
• Repeat pregnancy test, if indicated
• Repeat testing for gonorrhoea or chlamydia after 2 to 4 weeks in those with persisting symptoms, antibiotic resistance pattern (gonorrhoea only), poor compliance with antibiotics and/or tracing of sexual contacts indicating the possibility of persisting or recurrent infection

The following are recommended if the initial test for M. genitalium is positive:

• treatment with moxifloxacin. This agent currently has good microbiological activity against M. genitalium (Grade 1D)
• repeat testing for M. genitalium following treatment to ensure microbiological clearance. Treatment failure following the use of any of the recommended regimens has been reported but is least likely following treatment with moxifloxacin. The optimal time for testing after starting treatment is not known but 4 weeks is recommended based on expert opinion (Grade 1D)

Sexual Partners

Current male partners should be contacted and offered screening for gonorrhoea and chlamydia.

Other recent sexual partners may also be offered screening - tracing of contacts within 6 months of symptom onset is recommended but this may be influenced by sexual history (Grade 2D)

In women with confirmed M. genitalium infection, their male partner(s) should be offered testing for M. genitalium and, if positive, treated appropriately and concurrently with the index case

Because many cases of PID are not associated with gonorrhoea, C. trachomatis or M. genitalium, broad spectrum empirical therapy should also be offered to male partners e.g. doxycycline 100mg twice daily for 1 week (Grade 2D)

Partners should be advised to avoid intercourse until they and the index patient have completed the treatment course (Grade 2D)

An 2019 interim update has been made to the 2018 PID Guidelines. These are available here. The changes are reflected in the edited content above. All changes from the original 2018 guideline are highlighted in yellow text. You may download the original 2018 guideline here.