Pelvic inflammatory disease

Background

• Upper genital tract infection in women that involves infection of any combination of endometrium, fallopian tubes, and peritoneum

Microbiology

• Often polymicrobial
• Most commonly associated with Chlamydia trachomatis or Neisseria gonorrhoeae
• Other contributory microbes include:
  • Other sexually-transmitted organisms
    • Herpes simplex virus
    • Trichomonas vaginalis
  • Genitourinary microbiota
    • Mycoplasma genitalium
    • Mycoplasma hominis
    • Ureaplasma urealyticum
  • Anaerobes
    • Bacteroides species
    • Peptostreptococcus species
    • Prevotella species
  • Aerobes
    • Escherichia coli
    • Gardnerella vaginalis
    • Haemophilus influenzae
    • Streptococcus species

Epidemiology

• About 10-15% of women have at least one episode

Clinical Manifestations

• Pelvic or abdominal pain is the main complaint
• May be febrile and have adnexal, uterine, or cervical motion tenderness
• May present with tubo-ovarian abscess
• Minimum diagnostic criteria for treatment include lower abdominal pain, adnexal tenderness, and cervical motion tenderness
• Additional supportive criteria include
  • Fever >38.3ºC
  • Presence of leukocytes on saline microscopy of vaginal secretions
  • Elevated ESR or CRP
  • Diagnosed gonorrhea or chlamydia

Complications

• Short-term:
  • Fitz-Hugh-Curtis syndrome
  • Tubo-ovarian abscess
• Long-term:
  • Ectopic pregnancy
  • Infertility
  • Chronic pelvic pain

Differential Diagnosis

• Gynecologic/obstetrical
  • Complications of pregnancy
    • Ectopic pregnancy
  • Endometriosis
  • Endometritis
  • Adnexal disorders
  • Mentrual disorders
• Gastrointestinal
  • Appendicitis
  • Gastroenteritis
  • Inflammatory bowel disease
• Genitourinary
  • Cystitis
  • Pyelonephritis
  • Nephrolithiasis
• Musculoskeletal causes
• Neurologic causes

Investigations

• No combination of routine investigations (including swabs and ultrasound) can be used to completely rule out PID
• Laboratory investigations
  • β-hCG to rule out ectopic pregnancy
  • Endocarvical swabs for gonorrhea and chlamydia, and possibly HSV
  • Vaginal swabs for culture, pH, whiff testing, wet preps, and Gram stain
• Radiography
  • Ultrasound can be helpful, especially for tuboovarian abscess
  • Ideally done as transvaginal ultrasound

Diagnosis

• Definitive diagnosis is rarely obtained; more commonly, the disease is treated based on clinical findings
• Definitive diagnostic criteria include:
  • Endometrial biopsy with evidence of endometritis
  • Transvaginal ultrasound showing thickened fluid-filled tubes, with or without free pelvic fluid or tubo-ovarian complex
  • Laparoscopy showing findings of PID, including fallopian tube erythema or mucopurulent exudates

Management

• All patients must have a β-hCG to rule out pregnancy
• Criteria for hospitalization include:
  • Possible surgical emergency
  • Pregnancy
  • No response to oral antibiotics
  • Unable to tolerate oral antibiotics
  • Severe illness, nausea and vomiting, or high fever
  • Presence of tubo-ovarian abscess
  • Pediatric patients
• There are many possible regimens
  • Fluoroquinolones and doxycycline are contraindicated in pregnancy and breastfeeding
  • Often recommended to add metronidazole to any regimen that does not have adequate anaerobic coverage, though it is unclear whether this makes any difference
  • Only consider fluoroquinolones if there is susceptibility testing done or a test of cure is possible
  • First-line regimens
    • Cefoxitin 2 g IV q6h plus doxycycline 100 mg IV/PO q12h, stepped down to oral doxycycline once clinical improvement to complete 14 days
    • Clindamycin 900 mg IV q8h plus gentamicin 2mg/kg loading dose then 1.5 mg/kg q8h maintenance dose (or 5 mg/kg q24h dosing), steped down to doxycycline or clindamycin 450 mg PO qid to complete 14 days
  • Alternative regimens
    • Ofloxacin 400 mg IV q12h or levofloxacin 500 mg IV daily, ± metronidazole 500 mg IV q8h
    • Ampicillin-sulbactam 3 g IV q6h plus doxycycline 100 mg IV/PO q12h
    • Ciprofloxacin 200 mg IV q12h plus doxycycline 100 mg IV/PO q12h ± metronidazole 500 mg IV q8h
  • Outpatient regimens
    • Ceftriaxone 250 mg IM once plus docycycline 100 mg PO bid for 14 days, ± metronidazole 500 mg IV q8h
    • Cefoxitin 2 g IM once plus probenecid 1 g po once plus doxycycline 100 mg PO bid for 14 days, ± metronidazole 500 mg IV q8h
    • Another third-generation cephalosporin plus doxycycline 100 mg PO bid for 14 days, ± metronidazole 500 mg IV q8h
    • Ofloxacin 400 mg PO bid for 14 days, ± metronidazole 500 mg IV q8h
    • Levofloxacin 500 mg PO daily, ± metronidazole 500 mg IV q8h
• If an intrauterine device is in situ, remove it only after at least 2 doses of antibiotics have been given
• Pain should start to improve within 48 to 72 hours of antibiotics; if it does not, then consider further investigations
• Rule out other sexually-transmitted infections, including HIV and syphilis
• Immunize against hepatitis B and HPV if indicated
• Partners should be screened and treated

Further Reading

• Management and treatment of specific syndromes – Pelvic Inflammatory Disease (PID). Canadian Guidelines on Sexually Transmitted Infections.