An Update on Pelvic Inflammatory Disease

We last covered PID and TOA on the podcast in February 2019 — and since then, as with our gonorrhea and chlamydia update, have some new updates to reflect the 2021 CDC Treatment Guidelines.

What is PID/TOA? 

  • PID: pelvic inflammatory disease 

    • This is a wide variety of inflammatory disorders of the upper female genital tract, including: 

      • Endometritis

      • Salpingitis

      • TOA: tubo-ovarian abscess

      • Pelvic peritonitis 

    • Caused by many infectious diseases. 

      • Most common: N. gonorrhoeae and C. trachomatis (gonorrhea and chlamydia)

        • 50% of PID diagnoses test positive for GC/CT, though this proportion is decreasing.

    • Other organisms that can be implicated:

      • Anaerobes, 

      • G. vaginalis 

      • H. influenzae

      • Enteric GNRs

      • Strep agalactiae

      • Cytomegalovirus 

      • Trichomonas (Trichomonas vaginalis)

      • Mycoplasima hominis and M. genitalium

      • Ureaplasma urealyticum

Diagnosis of PID

  • Can be difficult because of many vague symptoms, and some are asymptomatic 

  • Differential diagnosis is broad for abdominopelvic pain: 

    • Appendicitis 

    • Ectopic pregnancy

    • Ovarian torsion or ovarian cysts

    • Diverticulitis

    • Functional GI pain, IBS, IBD

    • Etc. etc. etc. 

  • A presumptive dx should be made, and treatment started,

    • In sexually active women and those at risk for STIs experiencing pelvic/lower abdominal pain, if no other cause for illness can be identified,

    • and if they have 1 or more of these minimum clinical criteria

    • Cervical motion tenderness 

    • Uterine tenderness 

    • Adnexal tenderness  

  • One or more of the following can be used to enhance specificity of the minimal clinical criteria: 

    • Oral temp > 101 F (38.3) 

    • Abnormal cervical mucopurulent discharge or friability 

    • Presence of abundant WBC on saline microscopy of vaginal fluid 

    • Elevated erythrocyte sedimentation rate 

    • Elevated C-reactive protein 

    • Laboratory documentation of cervical infection with N. gonorrhoeae or C. trachomatis 

  • Even more specific criteria can include:

  • Endometrial biopsy with histopathologic evidence of endometritis 

  • TVUS or MRI showing thickened, fluid-filled tubes with or without free fluid or tubo-ovarian complex

  • Laparoscopic findings of PID (Fitz-Hugh-Curtis syndrome

What should I do if I think someone has PID?

  • Testing:

  • HIV

    • Testing recommended by CDC “in all persons seeking STI testing who do not have a known diagnosis of HIV.” 

  • GC/CT

    • 50% will test positive, so they are high yield for PID testing.

    • NAAT testing is preferred method.

      • Patient self-collected swabs are just as accurate as clinician-collected.

      • First void urine is most sensitive; decreases with later voids during the day.

        • Urine testing may miss over 400k infections per year in USA - vaginal swab testing should be offered first, and patient-collected may help improve acceptability.

  • Imaging

    • Not recommended outright by CDC in PID evaluation.

    • Will frequently be part of your evaluation in a differential diagnosis

      • TVUS - may continue to have cervical motion tenderness, can demonstrate TOA. Can also demonstrate other GYN pathologies.

      • CT/MRI - unlikely to demonstrate specific findings for PID outside of large TOAs.

  • Treatment:

    • Primary Considerations: 

  • Choice of medication:

    • Treatment is empiric, requiring broad spectrum coverage of likely pathogens

    • All treatment types should be effective against gonorrhea and chlamydia 

  • Need for hospitalization:

    • Recommended if:

      • A surgical emergency (ie. appendicitis) cannot be excluded

      • Presence of tubo-ovarian abscess 

      • Pregnancy

      • Severe illness including nausea, vomiting, or high fever,

      • Inability to tolerate or follow outpatient regimen

      • Failed outpatient therapy based on follow up

    • Parenteral treatments

      • Ceftriaxone (1g IV q24 hrs) + doxycycline (100 mg oral or IV q12hrs) + metronidazole (500mg oral or IV q12h).

      • Cefoxitin (2g IV q6hrs) + doxycycline (100mg oral or IV q12hrs) 

      • Cefotetan (2g IV q12h) + doxycycline (100mg oral or IV q12hrs)

    • Because of pain associated with IV infusion, doxycycline should be given orally whenever possible.

    • Oral and IV doxycycline and metronidazole have similar bioavailability

  • Alternative regimens pending allergies and antibiotic availability:

    • Clindamycin (900 mg IV q8hrs) + gentamicin (2mg/kg loading dose IV or IM, then maintenance of 1.5mg/kg every 8 hrs, or single daily dosing of 3-5mg/kg) 

    • Ampicillin-sulbactam (Unasyn) 3g IV q6hrs + doxycycline 100mg q12hrs  

  • Goal of parenteral therapy will be to transition to oral antibiotics within 24-48 hours if clinical improvement.

    • Those with TOA should have at least 24 hours of inpatient observation

    • IM/Oral treatment - For continuation of inpatient treatment, or start here in those with mild-to-moderate symptoms of acute PID. 

  • Clinical outcomes are similar to those treated with IV therapy, but if women don’t respond in 72 hours, should be re-evaluated and treated with IV

    • Ceftriaxone 500mg IM x1 + doxycycline 100mg BID x14 days + metronidazole 500 mg BID x14 days 

    • Cefoxitin 2g IM + Probenecid 1g orally + doxycyline 100mg BID x14 days + metronidazole 500mg BID x14 days 

    • Some other 3rd generation cephalosporin + doxy + metronidazole 

  • If starting with outpatient treatment, improvement should be documented by follow up within 72 hours.

    • If no improvement has occurred, then hospitalization, assessment of the antimicrobial regimen, and considering potential additional diagnostics (imaging, laparoscopy) are indicated.

  • Retesting should occur at 3 months after treatment, regardless of treatment of sex partners, to assess for reinfection.

    • Patients should refrain from sex until treatment is completed, symptoms resolved, and sex partners have been treated.

    • Sex partners within previous 60 days of patients with PID should also be treated presumptively for gonorrhea and chlamydia

      • This is regardless of PID etiology or pathogens isolated 

      • Consider expedited partner therapy (EPT).

Managing TOAs 

  • Surgical drainage indicated if:

    • Failure to respond to treatment within 48-72 hours 

    • Clinical decline (ie. becoming septic) 

  • Likelihood of need for surgical intervention is related to the size of TOA: 

    • 60% of those with abscess >10cm 

    • 30% in 7-9cm 

    • 15% in those of 4-6 cm

Special considerations for treatment in certain populations:

  • Pregnancy

    • Pregnant patients with PID are at high risk of morbidity, pregnancy loss, preterm delivery.

    • Hospitalization and consultation with ID are recommended.

  • Persons with HIV

    • Patients with HIV may be more likely to have TOA, though symptoms are similar overall to those without HIV.

    • No data currently to suggest more aggressive therapy is needed in patients with HIV.

  • If patient has an IUD:

    • IUD is not required to be removed with a diagnosis of PID.

    • However, if there is no clinical improvement in 48-72 hours, then should consider removing the IUD.

Pelvic Inflammatory Disease & Tubo-ovarian Abscess

Before we get to the meat of today’s topic… we’re pleased to announce a partnership with the OBG Project. They have excellent resources, and a new product called OBG First. PGY-4 residents can get OBG First for one year for absolutely free — check out the website and follow the instructions, and a coupon code will get sent to your inbox.

And now for PID! The CDC guidelines, as always, are super helpful further reading.

The diagnosis of PID can be challenging. In the absence of other causes, one of the following three findings must be present:
- Cervical motion tenderness
- Uterine tenderness
- Adnexal tenderness

There are several additional criteria that can enhance the specificity of diagnosis:
- Oral temp > 101 F (38.3)
- Abnormal cervical mucopurulent discharge or friability
- Presence of abundant WBC on saline microscopy of vaginal fluid
- Elevated erythrocyte sedimentation rate
- Elevated C-reactive protein
- Laboratory documentation of cervical infection with N. gonorrhoaea or C. trachomatis

Even more specific criteria include certain other tests, including:
- Endometrial biopsy with histopathologic evidence of endometritis
- TVUS or MRI showing thickened, fluid-filled tubes with or without free fluid, or tubo-ovarian complex
- Laparoscopic findings of PID (remember Fitz-Hugh-Curtis?)

We review indications for hospitalization versus outpatient treatment for PID, but the big ones to remember include:
- Inability to exclude other surgical emergencies
- Pregnancy
- Severe illness
- Inability to tolerate or follow outpatient therapy,
- Failed response to outpatient therapy in 48-72 hours.

Finally, we go over treatments for PID, straight from the CDC:

CDC STD 2015 Guidelines.

CDC 2015 STD Guidelines.

And remember:
- Clinical follow up should be arranged in 48-72 hours after hospitalization or after initiation of outpatient therapy, to ensure response.
- Tubo-ovarian abscess < 10 cm rarely need surgical intervention. However, percutaneous drainage is an option that often does help to expedite response to therapy.

Further reading from the OBG Project:
- Unexplained Pelvic Pain
- CDC treatment guidelines
- The ABCs of PID Diagnosis