Description

• Pelvic inflammatory disease (PID) is an infection of the upper female genital tract, including the uterus, fallopian tubes, and ovaries. PID is commonly an ascending polymicrobial infection acquired through retrograde movement of microorganisms from the lower genital tract.
• PID is concerning due to its potential impact on fertility.
• Mild to moderate PID is defined by the absence of a tubo-ovarian abscess (TOA). Severe PID involves systemic symptoms or presence of a TOA.
• Diagnosis is challenging due to nonstandardized definitions, lack of definitive tests, and varying symptoms (1)[C].

Epidemiology

Most commonly affects sexually active patients aged 15 to 24 years (1)[C].

Etiology and Pathophysiology

Multiple organisms cause PID, and polymicrobial infections are common.

• Chlamydia trachomatis and Neisseria gonorrhoeae, once considered the primary pathogens, are now identified in only 22–50% of cases.
• Mycoplasma genitalium infection is seen in ~4–22% of females diagnosed with PID, with some studies reporting upward of 60%. The latest study showed a 67% increase in odds of developing PID with an Mycoplasma genitalium infection (2)[A].
• Common flora and causes of bacterial vaginosis including aerobic and anaerobic species (e.g., Gardnerella vaginalis and Escherichia coli) are increasingly implicated (2)[A].
• Possible mechanisms for ascent from the lower genital tract include (i) travel from cervix to endometrium to salpinx to peritoneal cavity; (ii) lymphatic spread via infection of the parametrium; and (iii) hematogenous route, which is rare.

Risk Factors

• Sexually active and age <25 years
• New sexual partner or sexual partner with symptoms or known STI
• Two or more sexual partners in the last year (1)[C]
• Inconsistent condom use
• Gynecologic procedures that break the cervical barrier including endometrial biopsy, curettage, hysterosalpingography (HSG), hysteroscopy, in vitro fertilization, and insertion of IUD in the last 3 weeks.
• Other factors associated with PID:
  • Previous history of PID (10–25% recurrence)
  • Cervical ectopy
  • History of C. trachomatis; 10–40% develop PID.
  • History of gonococcal cervicitis; 10–20% develop PID (3)[A].

General Prevention

• Educational programs about safe sex practices such as condom use
• The U.S. Preventive Services Task Force recommends annual chlamydia screening for all sexually active women <25 years and for those ≥25 years at increased risk (e.g., new or multiple sex partners), with moderate evidence that it reduces cases of PID (1)[C].
• Routine STI screening in pregnancy
• STI screenings for those with new genital lesions or abnormal discharge

Commonly Associated Conditions

• In a patient with an IUD and a pelvic abscess, suspect Actinomyces infection and treat with penicillin.
• Rupture of an adnexal abscess is rare but life-threatening, requiring early surgical exploration (1)[C].
• Chlamydial or gonococcal perihepatitis, called Fitz-Hugh-Curtis syndrome, can accompany PID, causing severe pleuritic right upper quadrant pain, in 4–6% of PID cases (2)[A].
• Women presenting with acute pyelonephritis should also be evaluated for PID and STIs.

History

• Lower abdominal/pelvic pain: dull, aching/crampy, bilateral, constant; worsened by motion, exercise, or coitus
• New/abnormal vaginal discharge (~75% of cases) or unanticipated/postcoital bleeding (~40% of cases)
• Fever, chills, dyspareunia
• Low back pain
• Dysuria
• Recent HSG or other procedure breaking the uterine barrier
• IUD insertion in the past 21 days

Physical Exam

Fever; lower abdominal pain; cervical motion, uterine, or adnexal tenderness; evidence of cervicitis with/without vaginal discharge

Differential Diagnosis

Appendicitis, constipation, gastroenteritis, ectopic pregnancy, ovarian tumor/torsion, hemorrhagic/ruptured ovarian cyst, endometriosis/dysmenorrhea, functional pelvic pain, inflammatory bowel disease, diverticulitis, UTI/pyelonephritis, nephrolithiasis

Diagnostic Tests & Interpretation

General Measures

• An IUD does not need to be removed. Reassess the patient in 48–72 hours; if no clinical improvement, consider removal.
• Treatment should cover key pathogens (CT, NG, and polymicrobial infections with anaerobic coverage), regardless of test results (3)[A].

Medication

Surgery/Other Procedures

Reserved for failures of medical treatment and suspected ruptured adnexal abscess causing acute surgical abdomen

Admission, Inpatient, and Nursing Considerations

• Criteria for hospitalization if any of the following:
  • Surgical emergencies (e.g., appendicitis) can’t be excluded.
  • Pregnancy
  • TOA
  • Severe illness, nausea or vomiting, unable to follow or tolerate outpatient regimen, or fever >101°F
  • Failure to respond to 72 hours of oral antibiotics (1)[C]
• For inpatient treatment of PID, the CDC recommends the following:
  • Parenteral regimen A
    • Ceftriaxone 1 g IV every 24 hours plus doxycycline 100 mg PO or IV every 12 hours plus metronidazole 500 mg PO or IV every 12 hours.
    • Alternatively, cefotetan 2 g IV BID or cefoxitin 2 g IV q6h plus doxycycline 100 mg PO or IV BID; this regimen does not require additional anaerobic coverage with metronidazole.
    • Parenteral therapy for 24 to 48 hours after clinical improvement; oral doxycycline is preferred due to its similar bioavailability to IV. Continue doxycycline and metronidazole for a total of 14 days.
  • Parenteral regimen B
    • Clindamycin 900 mg IV q8h plus gentamicin loading dose IV or IM (2 mg/kg) followed by a maintenance dose (1.5 mg/kg) q8h or single daily dosing at 3 to 5 mg/kg can be substituted.
    • Parenteral therapy may be discontinued 24 hours after clinical improvement. Oral therapy with doxycycline (as above) or clindamycin 450 mg PO QID should be continued to complete 14 days.
  • Parenteral regimen C: ampicillin/sulbactam 3 g IV every q6h doxycycline 100 mg PO or IV BID
• PID in pregnancy requires hospitalization, infectious disease consultation, and parenteral antibiotics due to high risk of maternal morbidity, perinatal mortality, and preterm delivery (1)[C].

Follow-up Recommendations

Arranging follow-up within 48 to 72 hours and providing clear patient education are key to ensuring good patient outcomes.

Patient Education

• Abstain from sexual contact until complete treatment of patient and partner.
• Consistent and correct condom use
• Offer hepatitis B and human papillomavirus (HPV) vaccines to eligible patients.
• Advise comprehensive STI screening.
• Offer HIV preexposure prophylaxis (PrEP) to patients with new STI or PID.
• IUD insertion poses a low risk of PID, even with prior/current STI diagnosis.

Prognosis

• PID has a high morbidity: ~18% become infertile, 29% develop chronic pelvic pain, and 0.6% have an ectopic pregnancy.
• Prognosis is good with early effective therapy but poor if delayed.
• Nongonococcal, nonchlamydial PID is linked to more severe PID and worse fertility outcomes.

Complications

• TOA occurs in 7–16% of patients before presentation; 1/3 of those hospitalized with PID
• Recurrent infection occurs in 20–25% of patients.
• Risk of ectopic pregnancy increases 7- to 10-fold with prior PID.
• Tubal infertility in 8%, 19.5%, and 40% of patients after 1, 2, and 3 episodes of PID, respectively.
• Chronic pelvic pain in 20–30% of cases is related to adhesions, chronic salpingitis, or recurrent infection.
• Hydrosalpinx: After PID resolves, fallopian tube fills with sterile fluid and becomes blocked, associated with pain and infertility.

Additional Reading

https://www.cdc.gov/std/treatment-guidelines/pid.htm

ICD-10

• N70.0 Acute salpingitis and oophoritis
• N70 Salpingitis and oophoritis
• N71.0 Acute inflammatory disease of uterus
• N73.1 Chronic parametritis and pelvic cellulitis
• N73.3 Female acute pelvic peritonitis
• N70.03 Acute salpingitis and oophoritis
• N73.9 Female pelvic inflammatory disease, unspecified
• N73.8 Other specified female pelvic inflammatory diseases
• N70.01 Acute salpingitis
• N73.6 Female pelvic peritoneal adhesions (postinfective)
• N73.2 Unspecified parametritis and pelvic cellulitis
• N70.02 Acute oophoritis
• N70.1 Chronic salpingitis and oophoritis
• N70.93 Salpingitis and oophoritis, unspecified
• N70.9 Salpingitis and oophoritis, unspecified
• N72 Inflammatory disease of cervix uteri
• N70.92 Oophoritis, unspecified
• N73 Other female pelvic inflammatory diseases
• N71.1 Chronic inflammatory disease of uterus

SNOMED

• 198159006 Chronic parametritis and pelvic cellulitis
• 198142001 Chronic salpingo-oophoritis
• 198130006 Female pelvic inflammatory disease
• 237044002 Chronic pelvic inflammatory disease
• 237037006 Acute pelvic inflammatory disease
• 280483007 Parametritis
• 266581008 Acute salpingo-oophoritis
• 31354001 Endocervicitis
• 37610005 Inflammation of cervix
• 62394006 Female pelvic peritoneal adhesions
• 76047005 Oophoritis
• 188463006 Chlamydial pelvic inflammatory disease
• 271488001 Mycoplasmal pelvic inflammatory disease
• 698628000 Postabortal pelvic inflammatory disease
• 198242009 Female gonococcal pelvic inflammatory disease
• 198175009 Female syphilitic pelvic inflammatory disease
• 198241002 Female tuberculous pelvic inflammatory disease
• 722830001 Acute female pelvic inflammatory disease following procedure
• 722522009 Female pelvic inflammatory disease caused by Mycoplasma genitalium