Pelvic Inflammatory Disease

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  • Pelvic inflammatory disease (PID) is an infectious and inflammatory disorder of the upper female genital tract, including the uterus, fallopian tubes, ovaries, and adjacent pelvic structures. It is community acquired from sexually transmitted organisms (1).
  • Salpingitis is the most important component due to its impact on future fertility.
  • Mild to moderate PID is defined as the absence of a tubo-ovarian abscess (TOA). Severe disease is defined as severe systemic symptoms OR the presence of a TOA (2).
  • Diagnosis may be challenging due to variation in signs and symptoms because many patients with PID have subtle or nonspecific symptoms (3).


  • Predominant age: 15 to 25 years; this number has remained constant since early 1900s.
  • Predominant sex: female only


PID is the most common gynecologic reason for admission in the United States accounting for 18 per 10,000 recorded hospital discharges (2). The estimated prevalence of self-reported lifetime PID was 4.4% in sexually experienced women ages 18 to 44 years (4).

  • Lifetime prevalence has decreased steadily since 1995 across all races (4).
  • Among those with no history of prior STI, lifetime PID prevalence was higher in black versus white women (6% vs. 2.7%). Among women with a prior STI, lifetime prevalence of PID was similar by race (10% vs. 10.3%) (4).

Etiology and Pathophysiology

Multiple organisms may be etiologic agents in PID. Most cases are polymicrobial. The proportion of PID cases due to Chlamydia trachomatis and Neisseria gonorrhoeae appears to be declining. Fewer than 50% of women diagnosed with acute PID have a test positive for either of these organisms.

  • C. trachomatis, N. gonorrhoeae, genital tract mycoplasmas (particularly Mycoplasma genitalium), aerobic and anaerobic (Bacteroides fragilis), and vaginal flora (e.g., Prevotella, peptostreptococci, Gardnerella vaginalis, Escherichia coli, Haemophilus influenzae) are recognized as etiologic agents. Mixed infections are common (1,5,6).
  • Many nongonococcal, nonchlamydial microorganisms recovered from upper genital tract in acute PID are associated with bacterial vaginosis.
  • The precise mechanism by which microorganisms ascend from the lower genital tract is unclear. Possible mechanisms include the following: (i) travel from cervix to endometrium to salpinx to peritoneal cavity; (ii) lymphatic spread via infection of the parametrium (from an IUD); and (iii) hematogenous route, although this is rare.
  • Of cases, 75% occur within 7 days of menses, when cervical mucus favors ascent of organisms.

Risk Factors

  • Sexually active and age <25 years
  • First sexual activity at young age (<15 years)
  • New/multiple sexual partners
  • Nonbarrier contraceptive methods (i.e., oral contraceptive pills)
  • Previous history of PID; 20–25% will have a recurrence.
  • Cervical ectopy
  • History of C. trachomatis; 10–40% will develop PID.
  • History of gonococcal cervicitis; 10–20% will develop PID.
  • Gynecologic procedures that break the cervical barrier such as endometrial biopsy, curettage, hysterosalpingography, hysteroscopy, in vitro fertilization, and insertion of IUD in the last 6 weeks

General Prevention

  • Educational programs about safer sex practices such as barrier contraceptives, especially condoms and spermicidal creams or sponges, provide some protection.
  • The U.S. Preventive Services Task Force recommends screening for chlamydia in all sexually active women <25 years and in those 25 years and older at increased risk (new sex partner/multiple sex partners). Moderate-quality evidence suggests that chlamydia screening reduces cases of PID (3)[A].
  • Routine STI screening in pregnancy
  • Early medical care with occurrence of genital lesions or abnormal discharge

Commonly Associated Conditions

  • If PID is suspected in a patient with an IUD and a pelvic abscess is present, an Actinomyces infection requiring penicillin treatment may be present.
  • Rupture of an adnexal abscess is rare but life threatening. Early surgical exploration is mandatory (5).
  • Chlamydial or gonococcal perihepatitis may occur with PID. This combination is called Fitz-Hugh–Curtis (FHC) syndrome and is characterized by severe pleuritic right upper quadrant pain. FHC syndrome complicates 10% of PID cases.
  • Plasma cell endometritis has also been seen in the majority of females with PID; the density of plasma cell infiltration has been related to severity of symptoms (5).

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