Pelvic Inflammatory Disease (PID) Diagnosis and Treatment

Etiology and Risk Factors

Pelvic inflammatory disease (PID) is primarily caused by sexually transmitted infections, most commonly Chlamydia trachomatis and Neisseria gonorrhoeae, along with a variety of anaerobic and aerobic bacteria that ascend from the lower genital tract to the upper genital tract 1, 2
The primary causative organisms include Chlamydia trachomatis, Neisseria gonorrhoeae, anaerobic bacteria, aerobic/facultative bacteria, and Mycoplasmas, with Chlamydia trachomatis found in 5-39% of cervical samples from women with PID and Neisseria gonorrhoeae found in 27-80% of cervical samples from women with PID 1
Bacterial vaginosis (BV) is often an antecedent to PID, with BV-associated organisms contributing to polymicrobial PID 1
Uterine instrumentation, hormonal changes during menstruation, retrograde menstruation, and individual organism virulence factors may contribute to the pathogenesis of PID 1
Between 10-40% of women with untreated gonococcal or chlamydial cervicitis develop clinical symptoms of acute PID 1

Empiric treatment should be initiated in sexually active young women at risk for STDs if uterine/adnexal tenderness or cervical motion tenderness is present and no other cause for illness can be identified 4
Additional criteria supporting PID diagnosis include oral temperature >101°F (>38.3°C), abnormal cervical or vaginal mucopurulent discharge, presence of white blood cells on saline microscopy of vaginal secretions, elevated erythrocyte sedimentation rate or C-reactive protein, and laboratory documentation of cervical infection with N. gonorrhoeae or C. trachomatis 4

Treatment regimens must provide empiric, broad-spectrum coverage of likely pathogens including N. gonorrhoeae, C. trachomatis, anaerobes, gram-negative facultative bacteria, and streptococci to prevent long-term sequelae such as infertility, ectopic pregnancy, and chronic pelvic pain 5
Recommended inpatient treatment regimens include cefoxitin or cefotetan plus doxycycline, or clindamycin plus gentamicin, with treatment continued for at least 48 hours after clinical improvement and then oral doxycycline for 10-14 days 6
Hospitalization is recommended for uncertain diagnosis, surgical emergencies, pelvic abscess, pregnancy, adolescents, severe illness, inability to tolerate outpatient regimen, failure to respond to outpatient therapy, or inability to arrange clinical follow-up within 72 hours 6

Prevention of lower genital tract infections with C. trachomatis and N. gonorrhoeae, early detection and prompt treatment of lower tract infections, and screening for C. trachomatis and N. gonorrhoeae in all women younger than 25 years and those at risk can help prevent PID 2
Untreated PID can lead to serious sequelae including chronic pelvic pain, infertility (12% after one episode, 25% after two episodes, and over 50% after three or more episodes), ectopic pregnancy, and intra-abdominal infections 2
Patients with tubo-ovarian abscess that does not respond to antibiotics should undergo surgical drainage 3
Prevention of long-term sequelae has been linked directly with immediate administration of appropriate antibiotics 7