PID is a community-acquired ascending infection that may affect the uterus, fallopian tubes, ovaries, and peritoneal cavity as it ascends. It is classically caused by a sexually transmitted agent, most commonly Neisseria gonorrhea and/or Chlamydia trachomatis. Rapid diagnosis and treatment are important to prevent the development of recurrent infections, chronic pain, infertility, ectopic pregnancy, and peritonitis.
Every year in the United States PID accounts for 2.5 million outpatient visits, 200,000 hospitalizations, and 100,000 surgical procedures. It is the most frequent gynecologic cause for emergency department visits (350,000/year) and costs an estimated total of $2 billion/year.
Risk factors include age range 15 - 25 (a > 35 year old have 1/7 chance of having PID), poor contraceptive habits, and many sexual partners ( > 4 in 6 months; RR 3.4), and frequent sex (> 6 times/week; RR 3.2)
The most common presentation is lower abdominal pain of less than 2 weeks duration, bilateral, and not predominantly referable to the GI or urinary tract. Patients may also have dysuria, dysmenorrhea, irregular uterine bleeding. and dyspareunia.
On physical examination, there is usually diffuse tenderness in the lower quadrants with rebound tenderness and decreased bowel sounds being common. On pelvic examination PID is very likely if there is purulent endocervical discharge, cervical motion tenderness (chandelier sign), and adnexal tenderness with bimanual examination. Rectovaginal examination can further support these findings. Fever occurs in about half of patients with PID.
Suspicion of PID should be high and antibiotic therapy should be initiated even without definitive diagnosis because the risk of developing sequelae left untreated is very high.
The following tests are recommended:
- Urine regnancy test to rule out an ectopic pregancy
- Microscopic exam of vaginal discharge in saline - assessing for WBCs
- nucleic acid amplification tests for chlamydia and gonococcus
- FOBT - positive test can suggest other diagnoses.
- Ultrasound to rule out ectopic pregnancy if there is a positive pregnancy test and to rule out ovarian torsion, cysts, and tuboovarian abscess (TOA) if there is suspicion
Most authorities recommend inpatient treatment for those who are pregnant, cannot take oral medication, have poor compliance, have severe clinical illness (high fevers, nausea, vomiting, severe pain), have an abscess, or for whom surgerical intervention is possible. Adolescent females and women > 35 years of age are often routinely treated as inpatients, but there is no data to support this practice.
The most important pathogens that must be targeted are chlamydia and gonococcus. Inpatient regimens cover a broader spectrum including strep, gram-negative enterics, and anaerobic organisms.
- Parenteral therapy:
- Cefoxitin (2g IV q6) or cefotetan (2g iV q12) plus doxycycline (100 mg PO q12)
- Clindamycin (900 mg IV q8) plus gentamicin (2mg/kg loading dose followed by 1.5mg/kg q8 maintenance dose).
- After 24 hours of sustained clinical improvment, oral therapy can be started.
- Oral therapy:
- Ceftriaxone (250 mg IM single dose) plus doxycycline (100mg PO bid for 14 days) with or without metronidazole (500mg PO bid for 14 days).
- Cefoxitin (2 g IM single dose) concurrently with probenecid (1 g PO single dose) plus doxycycline (100 mg PO bid for 14 days) with or without metronidazole (500 mg PO bid for 14 days).
It is imperative that sexual partners of the patient be treated as well. Patients should be counseled about contraception and the risk of an ectopc pregnancy.
Prognosis and complications
Recurrence rates amongst patients with PID is high. One study of low income AA age <19 and > 19 showed recurrence rates of 25 and 20 percent, respectively, at 84 months post-treatment. The most serious complication is tuboovarian abscesses since rupture can lead to sepsis, shock and death.
Chronic pelvic pain develops in up to one third of cases, with the more important risk factor being recurrence.
Infertility is increased several-fold in prevalence among those with PID. The most important risk factors are Chlamydial infection, delay in seeking care, multiple episodes of PID, and severity of infection.
PID is an important risk factor for ectopic pregnancies. The ratio of ectopic pregnancy to intrauterine pregnancy was 1:15, 1:6, and 1:3 after one, two, and three episodes of PID. And in women with a single, milk, or severe episode of PID the ratio of ectopic to intrauterine pregnancy was 1:35, 1:25, and 1:5.
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