Pelvic inflammatory disease (PID) is a polymicrobial infection of the upper female genital tract: the cervix, uterus, fallopian tubes, and ovaries; tubo-ovarian abscess may occur. PID is often caused by sexually transmitted infections. Common symptoms and signs include fever, pelvic or lower abdominal pain, mucopurulent cervical discharge, and cervical motion tenderness. Potential long-term complications include infertility, ectopic pregnancy, and chronic pelvic pain. Diagnosis is made with pelvic examination; complete blood count; testing of cervical specimens for Neisseria gonorrhoeae, Chlamydia trachomatis, and other infections; and sometimes ultrasound or laparoscopy. Treatment is with antibiotics.
Pelvic inflammatory disease (PID) may involve the cervix, uterus, fallopian tubes, and/or ovaries. Infection of the cervix (cervicitis) causes mucopurulent discharge. Infection of the fallopian tubes (salpingitis) and uterus (endometritis) tend to occur concurrently. If severe, infection can spread to the ovaries (oophoritis) and then the peritoneum (peritonitis). Salpingitis with endometritis and oophoritis, with or without peritonitis, is often called salpingitis even though other structures are involved. Pus may collect in the tubes (pyosalpinx), and an abscess may form (tubo-ovarian abscess).
Etiology of PID
PID results from microorganisms ascending from the vagina and cervix into the uterus and fallopian tubes. The sexually transmitted infections Neisseria gonorrhoeae and Chlamydia trachomatis are common causes of PID. Mycoplasma genitalium, which is also sexually transmitted, can also cause or contribute to PID. Incidence of sexually transmitted PID is decreasing; approximately 50% of patients with acute PID test positive for gonorrhea or chlamydia (1).
PID usually also involves other aerobic and anaerobic bacteria, including pathogens that are associated with bacterial vaginosis. Vaginal microorganisms such as Haemophilus influenzae, Streptococcus agalactiae, and enteric gram-negative bacilli can be involved in PID, as can Ureaplasma species. Vaginal inflammation and bacterial vaginosis contribute to the ascending spread of vaginal microorganisms.
PID due to N. gonorrhoeae is usually more acute and causes more severe symptoms than that due to C. trachomatis, which can be indolent. PID due to M. genitalium, like that due to C. trachomatis, is also mild and should be considered in women who do not respond to first-line therapy for PID.
Risk factors
PID occurs most commonly in young reproductive-age women. It is rare before menarche, after menopause, and during pregnancy. Risk factors include (2, 3):
Age < 25 years
Age at first sexual intercourse < 15 years
A new sexual partner within the past 12 months or ≥ 2 prior sexual partners
History of vaginal discharge or pelvic pain within the past 6 months
History of adverse pregnancy outcome
Being single
Nonwhite race
Low socioeconomic status
Etiology references
1. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. Published 2021 Jul 23. doi:10.15585/mmwr.rr7004a1
2. Simms I, Stephenson JM, Mallinson H, et al. Risk factors associated with pelvic inflammatory disease. Sex Transm Infect. 2006;82(6):452-457. doi:10.1136/sti.2005.019539
3. Hay PE, Kerry SR, Normansell R, et al. Which sexually active young female students are most at risk of pelvic inflammatory disease? A prospective study. Sex Transm Infect. 2016;92(1):63-66. doi:10.1136/sextrans-2015-052063
Symptoms and Signs of PID
Pelvic inflammatory disease commonly presents with fever, pelvic or lower abdominal pain, vaginal discharge (when cervical discharge passes through the vagina), and/or abnormal uterine bleeding. Some patients report dyspareunia, dysuria, upper abdominal pain, nausea, and vomiting. However, many patients are asymptomatic or have mild symptoms.
Lower abdominal tenderness, often with rebound tenderness, is present on examination. Pelvic examination findings include cervical motion tenderness, uterine tenderness, and bilateral adnexal tenderness. A palpable adnexal mass suggests tubo-ovarian abscess.
On speculum examination, cervicitis is typically present, and the cervix is erythematous and friable (bleeds easily). Mucopurulent cervical discharge is common.
A tubo-ovarian abscess (collection of pus in the adnexa) develops in approximately 15% of women with salpingitis. It can accompany acute or chronic infection and is more likely if treatment is late or incomplete. Pain, fever, and peritoneal signs are usually present and may be severe. An adnexal mass may be palpable, although extreme tenderness may limit the examination. The abscess may rupture, causing progressively severe symptoms and possibly septic shock.
Diagnosis of PID
Pelvic examination
Cervical tests for Neisseria gonorrhoeae and Chlamydia trachomatis
Sometimes pelvic ultrasound
Rarely laparoscopy
Clinicians should have a high index of suspicion for pelvic inflammatory diseases (PID), particularly in patients with risk factors, because clinical presentation is variable and even minimally symptomatic infection may have severe sequelae.
A presumptive diagnosis of PID should be made and treatment initiated for sexually active young women and other women at risk for STIs if they are experiencing pelvic or lower abdominal pain, no cause for the illness other than PID can be identified, and if 1 or more of the following 3 minimum clinical criteria are present on pelvic examination:
Cervical motion tenderness
Uterine tenderness
Adnexal tenderness
PID is primarily a clinical diagnosis and routine measurement of white blood cell count or complete blood count measurements is not required to diagnose PID (1). An elevated erythrocyte sedimentation rate (ESR) is identified as one of several additional criteria that can enhance diagnostic specificity when used with clinical criteria. A pregnancy test should be performed in reproductive-age women.
If PID is suspected, NAAT (nucleic acid amplification test) of cervical specimens for N. gonorrhoeae and C. trachomatis (which is approximately 99% sensitive and specific) is performed or, if NAAT is unavailable, cervical cultures are taken. However, upper tract infection is possible even if tests for cervical infection are negative.
If a patient cannot be adequately examined because of tenderness, imaging studies are performed as soon as possible. Ultrasound is the preferred first line test. If ultrasound is not available or is inconclusive, other imaging modalities like CT scan may be performed to evaluate for abscess, including tubo-ovarian abscess, and to exclude other etiologies of lower abdominal pain (eg, appendicitis).
Differential diagnosis
If a pregnancy test is positive, ectopic pregnancy, which can produce similar findings, should be considered.
Other common causes of pelvic pain include endometriosis, adnexal torsion, ovarian cyst rupture, and appendicitis. Differentiating features of these disorders are discussed elsewhere in The Manual.
Fitz-Hugh-Curtis syndrome may mimic acute cholecystitis but can usually be differentiated by evidence of salpingitis during pelvic examination or, if necessary, with ultrasound.
Diagnosis reference
1. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. Published 2021 Jul 23. doi:10.15585/mmwr.rr7004a1
Treatment of PID
Antibiotics to cover Neisseria gonorrhoeae, Chlamydia trachomatis, and vaginal flora
When a PID diagnosis is suspected but cervical infection has not been confirmed or the patient does not meet all clinical criteria, empiric treatment of PID is given for several reasons:
Test results may take a few days.
Clinical criteria have a low sensitivity (1)
Not treating minimally symptomatic PID can result in serious complications.
Antibiotics are given empirically to cover N. gonorrhoeae, C. trachomatis, and vaginal flora, including anaerobes, and are modified based on laboratory test results.
Patients with clinically mild to moderate PID do not require hospitalization. Outpatient treatment regimens (see table ) usually also aim to eradicate bacterial vaginosis, which often coexists.
Sex partners of patients with N. gonorrhoeae or C. trachomatis infection should be treated.
Regimens for Treatment of Pelvic Inflammatory Disease
Treatment | Recommended Regimens | Alternative Regimens |
|---|---|---|
Parenteral† | Regimen A: Ceftriaxone 1 g IV every 24 hours PLUS Doxycycline 100 mg orally or IV every 12 hours PLUS Metronidazole 500 mg orally or IV every 12 hours Regimen B: Cefotetan 2 g IV every 12 hours OR Cefoxitin 2 g IV every 6 hours PLUS Doxycycline 100 mg orally or IV every 12 hours | Regimen C: Ampicillin/sulbactam 3 g IV every 6 hours PLUS Doxycycline 100 mg orally or IV every 12 hours Regimen D: Clindamycin 900 mg IV every 8 hours PLUS Gentamicin 2 mg/kg IV or IM (loading dose), followed by 1.5 mg/kg every 8 hours (maintenance dose); can be substituted with single daily dosing (3–5 mg/kg once a day) |
Oral or IM† | Regimen A: Ceftriaxone 500 mg IM in a single dose‡ PLUS Doxycycline 100 mg orally twice a day for 14 days WITH Metronidazole 500 mg orally twice a day for 14 days Regimen B: Cefoxitin 2 g IM in a single dose with probenecid 1 g orally administered concurrently in a single dose PLUS Doxycycline 100 mg orally twice a day for 14 days WITH Metronidazole 500 mg orally twice a day for 14 days Regimen C: Other parenteral 3rd-generation cephalosporin (eg, ceftizoxime, cefotaxime) PLUS Doxycycline 100 mg orally twice a day for 14 days WITH Metronidazole 500 mg orally twice a day for 14 days | Regimen D§: Levofloxacin 500 mg orally once a day for 14 days OR Moxifloxacin 400 mg orally once a day for 14 days WITH Metronidazole 500 mg orally twice a day for 14 days Regimen E: Azithromycin 500 mg IV once a day in 1 or 2 doses, followed by 250 mg orally once a day for a total duration of 7 days WITH OR WITHOUT Metronidazole 500 mg orally three times a day for 12 to 14 days |
Recommendations are from the Centers for Disease Control and Prevention. Workowski KA, Bachmann LH, Chan PA, et al: Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep 70(4):1-187, 2021 doi:10.15585/mmwr.rr7004a1 | ||
† Intramuscular or oral therapy can be considered for mild to moderate acute PID because the clinical outcomes with intramuscular/oral and parenteral therapy are similar. If patients do not respond to oral therapy within 72 hours, they should be reevaluated to confirm the diagnosis, and intravenous therapy should be given. | ||
‡ If patient weighs > 150 kg with documented gonococcal infection, 1 g of ceftriaxone should be administered. | ||
§ This regimen may be considered if the patient has a cephalosporin allergy, if community prevalence and individual risk of gonorrhea are low, and if follow-up is likely. Tests for gonorrhea must be performed before therapy is started, and the following management is recommended:
| ||
If patients do not improve after treatment that covers the usual pathogens, PID due to Mycoplasma genitalium should be considered. When resistance testing is available, treat M. genitalium with doxycycline (100 mg orally twice daily for 7 days) followed by either azithromycin (if macrolide sensitive, 1 g orally for 1 dose then 500 mg daily for 3 additional days) or moxifloxacin (if macrolide resistant, 400 mg orally once daily for 7 days) (2). If resistance testing is not available, treat with doxycycline followed by moxifloxacin.
Women with PID are usually hospitalized if any of the following are present:
Uncertain diagnosis, with inability to exclude a disorder requiring surgical treatment (eg, appendicitis)
Pregnancy
Severe symptoms or high fever
Tubo-ovarian abscess
Inability to tolerate or follow outpatient therapy (eg, due to vomiting)
Lack of response to outpatient (oral) treatment
In these cases, IV antibiotics (see table ) are started as soon as cultures are obtained and are continued until patients have been afebrile for 24 hours.
If patients do not respond to antibiotics within 48 to 72 hours, pelvic ultrasound or abdominal/pelvic CT scan are performed as soon as possible to exclude tubo-ovarian abscess.
If the diagnosis is uncertain after ultrasound or other imaging modalities and patients do not respond to antibiotic therapy, laparoscopy should be considered; purulent peritoneal material noted during laparoscopy is diagnostic of PID.
This photo shows a uterus and ovary that had been excised because of an ovarian abscess in a patient with pelvic inflammatory disease (PID).
CDC
Tubo-ovarian abscess may require more prolonged IV antibiotic treatment. Treatment with ultrasound- or CT-guided percutaneous or transvaginal drainage should be considered if response to antibiotics alone is incomplete or tubo-ovarian abscess size > 7 cm is present (3). Laparoscopy or laparotomy is sometimes required for drainage. Suspicion of a ruptured tubo-ovarian abscess requires immediate laparoscopy or laparotomy, depending on the provider. In women of reproductive age, surgery should aim to preserve the pelvic organs (with the hope of preserving fertility).
Treatment references
1. Brunham RC, Gottlieb SL, Paavonen J. Pelvic inflammatory disease. N Engl J Med. 2015;372(21):2039-2048. doi:10.1056/NEJMra1411426
2. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. Published 2021 Jul 23. doi:10.15585/mmwr.rr7004a1
3. Goje O, Markwei M, Kollikonda S, et al: Outcomes of minimally invasive management of tubo-ovarian abscess: A systematic review. J Minim Invasive Gynecol 28 (3):556–564, 2021. doi: 10.1016/j.jmig.2020.09.014
Complications of PID
Fitz-Hugh-Curtis syndrome (perihepatitis that causes upper right quadrant pain) may result from acute gonococcal or chlamydial salpingitis. Infection may become chronic, characterized by intermittent exacerbations and remissions.
Hydrosalpinx is fimbrial obstruction and tubal distention with nonpurulent fluid; it is usually asymptomatic but can cause pelvic pressure, chronic pelvic pain, dyspareunia, and/or infertility.
Salpingitis may cause tubal scarring and adhesions, which commonly result in chronic pelvic pain, infertility, and increased risk of ectopic pregnancy.
Key Points
The sexually transmitted pathogens Neisseria gonorrhoeae and Chlamydia trachomatis are common causes of PID, but infection is often polymicrobial.
PID can cause tubal scarring and adhesions, which commonly result in chronic pelvic pain, infertility, and increased risk of ectopic pregnancy.
Because even minimally symptomatic infection may have severe sequelae, index of suspicion should be high.
PCR and cultures are accurate tests; however, if results are not available at the point of care, empiric treatment is usually recommended.
Hospitalize women with PID based on clinical criteria (see above).
Drug Information for the Topic
