• Clinical science

Pelvic inflammatory disease

Abstract

Pelvic inflammatory disease (PID) is caused by a bacterial infection that spreads beyond the cervix to infect the upper female reproductive tract, including the uterus, fallopian tubes, ovaries, and surrounding tissue. The most common pathogens that cause PID are Chlamydia and Gonococci. Symptoms may vary considerably; while some women are asymptomatic, others may complain of mild pressure pain and discharge or present with signs of systemic inflammation such as fever and severe abdominal pain. Diagnosis is based on clinical findings and may be supported by ultrasound, PCR, and/or cultures of cervical and urethral discharge. Calculated parenteral antibiotic therapy is indicated in women with suspected PID. Complications include sterility due to impairment of the fallopian tubes.

Epidemiology

  • Lifetime prevalence in the US (women aged 15–44): ∼ 6%
  • > 1 million women experience an episode of PID/year.
  • PID is one of the most common causes of infertility.

References:[1][2][3]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

  • Pathogen
  • Risk factors
    • Multiple sexual partners, unprotected sex
    • A history of prior STIs and/or adnexitis
    • Infrequently: IUD [4], menstruation, former abortions, douching
    • Dysbiosis supports the development of PID.
  • Risk is lower during pregnancy but if occurs PID increases the risk of maternal morbidity and preterm births. [5]
  • Possible sites of infection
    • Cervix ; (cervicitis), or endometrium (endometritis)
    • Fallopian tubes (salpingitis), ovaries (oophoritis), or a combination of both (adnexitis)
    • Surrounding pelvic structures or even the peritoneum (peritonitis)

References:[6][7][4]

Clinical features

References:[8]

Diagnostics

  • Diagnosis is primarily based on clinical findings. Further diagnostic tests help confirm the diagnosis, especially in ambiguous cases.
  • Important diagnostic criteria
    • Patient history: most often a sexually active young woman
    • Lower abdominal pain
    • Vaginal examination
      • Cervical motion tenderness (CMT)
      • Uterine and/or adnexal tenderness
      • Purulent, bloody cervical and/or vaginal discharge
  • Blood tests: elevated ESR, leukocytosis
  • Pregnancy test: to rule out an (ectopic) pregnancy.
  • Cervical and urethral swab: gonococcal and chlamydial DNA (PCR) and cultures (see gonorrhea and chlamydia infections)
  • Imaging
    • Ultrasound: free fluid, abscesses, pyosalpinx/hydrosalpinx
    • Exploratory laparoscopy
      • Indication: in ambiguous cases and if patient does not respond to treatment
      • Findings
  • Culdocentesis: aspiration of intraperitoneal fluid from the pouch of Douglas
    • Reveals nature of the fluid (e.g., serous, purulent, bloody)
    • Culdocentesis is no longer a routine procedure and it has been largely replaced by ultrasound.

PID may present with symptoms of appendicitis due to periappendicitis or perihepatitis. Symptoms may also resemble those of an ectopic pregnancy!

PID should be suspected in young, sexually active women who present with lower abdominal pain and adnexal/cervical motion tenderness!

References:[9][2]

Differential diagnoses

Clinical features Diagnostic clues Therapy
Ectopic pregnancy
  • Lower unilateral abdominal pain and guarding
  • Vaginal bleeding
  • Amenorrhea
PID
  • Cervical discharge
  • Cervical motion tenderness (CMT)
Appendicitis
  • Initially diffuse epigastric pain
  • Later localized right lower quadrant pain
  • Nausea and vomiting
  • Fever
Kidney stones
  • Unilateral colicky flank pain
  • Pain may radiate to the lower abdomen and genital area
  • Destruction or removal of stone
Ovarian cyst rupture
  • Unilateral abdominal pain
  • Sudden onset during physical activity (exercise, sexual intercourse)
  • Continued surveillance or surgery

Cervicitis

  • Definition: inflammation of the uterine cervix
  • Etiology
    • Infectious (most common): C. trachomatis, N. gonorrhea, herpes simplex virus, T. vaginalis
    • Noninfectious : localized trauma (e.g., cervical caps, diaphragms, tampons), chemical irritation (e.g., contraceptive creams, latex exposure), malignancy
    • Risk factors: multiple partners, young age, new sexual partner within the last 6 months, unprotected intercourse
  • Clinical features
    • Often asymptomatic
    • Usually no fever
    • Vaginal discharge: may be purulent, blood-tinged, and/or malodorous
    • Dyspareunia
    • Postcoital or intermenstrual bleeding
    • Lower abdominal or pelvic pain
    • Symptoms of the underlying condition (e.g., genital lesions in HSV infections)
    • Physical examination
      • Abdominal palpation: tenderness/discomfort
      • Bimanual examination: motion tenderness of the cervix
      • Pelvic examination: erythematous, edematous, friable cervix ; possibly visible discharge
  • Diagnostics
    • Diagnosis mainly clinical
    • Further tests for identification of a pathogen
      • Assess vaginal secretions for appearance, pH , leukocyte count, and visible pathogens (e.g., protozoa in T. vaginalis infections)
      • Swab samples for bacterial culture
  • Treatment
  • Complications: PID

References:[10][11][12][9][13]

The differential diagnoses listed here are not exhaustive.

Treatment

  • Empirical antibiotic therapy (also consider coinfections!)
    • Outpatient regimen
    • Inpatient regimen (parental antibiotics)
      • Indications: no response to or unable to take outpatient oral regimen, non-compliance concerns (e.g., teenagers), high fever
      • Cefoxitin or cefotetan plus doxycycline or
      • Clindamycin plus gentamicin
      • Switch to oral therapy with doxycycline after clinical improvement.
  • It is better to overtreat rather than delay treatment if PID is suspected!

References:[4]

Complications

  • Short-term complications
  • Long-term complications
    • Tubo-ovarian abscess
    • Infertility: caused by adnexitis, adhesion of the fallopian tubes and ovaries, and tubal scarring (resulting in loss of ciliary action and tubal occlusion)
    • Ectopic pregnancy
    • Chronic salpingitis and hydrosalpinx

References:[9][2][3]

We list the most important complications. The selection is not exhaustive.