Pelvic Inflammatory Disease

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Diagnosis and reasoning

Fever and lower abdominal pain is an extremely common presentation, and may be due to a wide range of surgical and gynecological causes. However, in practice, the most common conditions implicated are urinary tract infections (UTI), acute appendicitis, acute diverticulitis, and pelvic inflammatory disease (PID). In this patient, the absence of urinary tract symptoms (such as frequency, urgency and dysuria) and the unremarkable urinalysis exclude a UTI. Appendicitis is clinically less likely, given the absence of anorexia and non-classical nature of the pain. However, atypical presentations are common, and this possibility should be kept in mind if the other conditions come up negative. Diverticulitis typically presents with left lower quadrant pain; while anorexia, nausea or vomiting, and gastrointestinal symptoms (such as bloating, diarrhea, or constipation) are frequent accompaniments. The absence of these findings make this diagnosis less likely. The deep dyspareunia of recent onset is a strong pointer towards PID, as is the bilateral adnexal tenderness (which is encountered in only a few conditions - PID, endometriosis, and rarely, ectopic pregnancy). Thus, this diagnosis is the most clinically likely so far. Pelvic ultrasonography is the imaging modality of choice in cases of suspected PID. In this patient, the findings of thickened fallopian tubes and free fluid in the pelvis have a sensitivity of 85% and a specificity of 100% for the diagnosis. As a substantial proportion of PID cases are caused by the sexually transmitted pathogens C. trachomatis and N. gonorrhoeae, the Royal College of Obstetricians and Gynaecologists (RCOG) of the United Kingdom recommends screening for these diseases in affected women. Note that the Centers for Disease Control (CDC) of the United States do not have specific recommendations in this regard. Chlamydial and Gonorrheal Nucleic Acid Amplification Tests (NAAT) have a high sensitivity and specificity for detection - and in this patient show that Chlamydial infection is indeed present. Appropriate empirical antibiotic therapy should be commenced immediately. Evidence on whether or not to remove intrauterine devices (IUD) is limited and conflicting. The current guidelines of the RCOG recommend removal, while those of the CDC leave the decision to the clinician, but recommend close followup of patients in whom the device is left in-situ. A laparotomy is not indicated in her current management. Nor is there a role for the anti-androgen Danazol.


Discussion

PID is a clinical syndrome associated with upper genital tract inflammation caused by the spread of micro-organisms from the lower to the upper genital tract. Around 1.5 million women in the United States are believed to be affected. The spectrum of clinical presentations ranges from endometritis to salpingitis, tubo ovarian abscesses and pelvic peritonitis. Many cases of PID are are secondary to sexually transmitted organisms such as Neisseria gonorrhoeae and Chlamydia trachomatis. However, Ureaplasma spp, Mycoplasma genitalium and certain vaginal flora (such as Gardnerella vaginalis, Haemophilus influenzae, Streptococcus agalactiae, and certain anaerobes) may also cause PID. The most important risk factor for PID is previous Chlamydial or Gonococcal infection. Other risk factors include young age, lack of barrier contraception, a high frequency of new partners, and low socioeconomic status. In addition, the risk of PID is increased in the first 3 to 4 weeks following insertion of an IUD. The signs and symptoms of PID vary greatly, with some women experiencing only subtle or mild symptoms. Others may experience lower abdominal pain, (deep) dyspareunia, back pain, fever and vomiting. There may also be symptoms of concurrent lower genital tract infection. The CDC guidelines suggest that PID should be suspected in sexually active young women who present with lower abdominal pain which cannot be attributed to any other cause, and who have one or more of the following clinical findings: cervical motion tenderness, uterine tenderness, or adnexal tenderness. Empirical antibiotic treatment can be commenced in such patients. Supportive laboratory findings include elevated ESR and/or C-Reactive Protein levels; the presence of N. gonorrhoeae or C. trachomatis cervicitis; and the presence of abundant polymorphonuclear leukocytes (PMCs) in a vaginal wet mount. Note that the specific diagnosis of PID requires either imaging, biopsy, or laparoscopy. A transvaginal ultrasound scan or abdominal MRI study showing thickened, fluid-filled tubes (with or without free pelvic fluid or a tubo-ovarian complex) is diagnostic. An endometrial biopsy showing histopathologic evidence of endometritis is also diagnostic, as are laparoscopic abnormalities consistent with PID. Antibiotic therapy is the mainstay of treatment. All regimens used should be effective against both Chlamydia trachomatis and N. gonorrhoeae. Many units additionally cover against anaerobic organisms. Outpatient therapy is generally safe in disease of mild to moderate severity. Hospitalization is necessary if the patient is pregnant, severely ill, or not responding to oral treatment. Surgical management should be considered in severe cases or when there is a pelvic abscess. If a sexually transmitted pathogen is detected, the patient should be screened for other sexually transmitted infections, and her partner(s) should be traced and evaluated. The long term sequelae of PID include infertility, ectopic pregnancy and chronic pelvic pain. Early diagnosis and treatment is key to avoid these complications.


Take home messages

  1. PID should be considered in all sexually active woman presenting with lower abdominal pain.
  2. A significant number of cases are secondary to Chlamydial or Gonorrheal infection.
  3. The risk of PID is increased during the first few weeks after insertion of an IUCD.
  4. Empirical treatment can be commenced upon clinical findings alone.

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  1. AFP: Drug Treatment of Common STDs: Part II. Vaginal Infections, Pelvic Inflammatory Disease and Genital Warts (October 1999)
  2. AFP: The Challenge of Pelvic Inflammatory Disease (March 2006)
  3. Centers for Disease Control and Prevention: Sexually Transmitted Diseases Treatment Guidelines: Pelvic Inflammatory Disease (2010)
  4. Clinical Obstetrics and Gynecology : Imaging of Acute Pelvic Pain (2009)
  5. Infectious Diseases in Obstetrics and Gynecology: A practical approach to the Diagnosis of Pelvic Inflammatory Disease (2011)
  6. RCOG Green-top Guideline No 32: Management of Acute Pelvic Inflammatory Disease (November 2008)
  7. Sexually Transmitted Infections: Pelvic inflammatory disease epidemiology: what do we know and what do we need to know? (200)