What is pelvic inflammatory disease (PID)?

Causes and Symptoms

Pelvic inflammatory disease (PID) is a polymicrobial infection of the upper genital tract. The microbes involved may be sexually transmitted organisms (such as Neisseria gonorrhea

or
Chlamydia trachomatis) and/or endogenous
bacteria found in the vagina (for example Staphylococcus, Streptococcus, or Bacteroides species). These microorganisms can travel from the lower genital tract (vagina, cervix) into the upper genital tract (uterus, Fallopian tubes, ovaries, and pelvic cavity) and establish infection there. Occasionally, PID can occur via another mechanism, such as infection and rupture of the appendix or lower gastrointestinal tract leading to spillage of bacteria into the pelvic cavity.

Most cases of PID are asymptomatic. In cases where symptoms occur, the patient has lower abdominal or pelvic pain. The Centers for Disease Control and Prevention (CDC) stipulates the diagnostic criteria for PID, noting that the diagnosis is made on clinical findings rather than on laboratory evidence. On abdominal examination, the lower abdomen is tender to palpation. Upon pelvic examination, either the cervix is tender upon movement by the examiner or one or both ovaries or Fallopian tubes is tender to palpation; both of these symptoms can be present as well. Other symptoms and signs include fever and abnormal cervical discharge.

Laboratory tests can be helpful in establishing a diagnosis when clinical symptoms are ambiguous and in emphasizing the need for partner treatment. The tests include blood tests that suggest systemic
inflammation (such as the erythrocyte
sedimentation rate) and cultures for N. gonorrhea or C. trachomatis. With ultrasound or other imaging techniques, fluid collections associated with the Fallopian tubes, ovaries, or elsewhere in the pelvic cavity can be consistent with PID.

On rare occasions, PID can spread to the upper abdomen, leading to pain and tenderness there. In particular, the infection can affect the region surrounding the liver, leading to Fitz-Hugh Curtis syndrome.

Long-term consequences of PID can be significant and can occur in asymptomatic as well as symptomatic patients. PID can cause scarring of the reproductive tract leading to infertility. PID increases the risk for ectopic pregnancy,
a potentially life-threatening condition. If the infection spreads beyond the reproductive tract, then organs such as the bowels may become involved in the infection as well. Any organs involved in the infection run the risk of becoming damaged and scarred. In addition to the acute pain of PID, the disease can also lead to chronic pelvic pain, which can be difficult to treat.

Treatment and Therapy

Pelvic inflammatory disease is usually treated in an outpatient setting, although severe cases require hospitalization with intravenous medications. Antibiotics are the first-line treatment for PID, which is most commonly treated empirically based on clinical suspicion. Because PID is polymicrobial, combinations of antibiotics, each targeted at different bacteria, are given simultaneously. One common regimen involves cefotetan plus doxycycline. Metronidazole is now added to many regimens as a third drug to cover for anaerobic organisms.

Since PID is usually sexually transmitted, therapy involves counseling regarding the prevention of sexually transmitted infections (STIs) and safer sexual techniques. Condoms and other barrier techniques decrease the spread of STIs. Anal penetration followed by vaginal penetration during intercourse may increase the risk of infection of the female reproductive tract. Testing for other STIs, such as hepatitis B and C and syphilis; wet prep testing for bacterial vaginosis and trichomonas; and screening for human immunodeficiency virus (HIV) is encouraged, since the risk factors for PID are similar to those for other STIs. Contact tracing is offered to notify sexual partners of their possible exposure to STIs and to encourage them to seek medical attention. Treatment of these partners can decrease reinfection of the patient from subsequent sexual encounters and prevent the partners from spreading infection to others.

Perspective and Prospects

One of the first reports of PID was from ancient Greece and involved a case in which pus from the pelvis was drained through the vagina. It was not until the 1880s, however, that the sequence of events starting from lower genital tract infection ascending to cause upper tract disease was recognized. With the widespread use of laparoscopy in the 1960s, a more accurate diagnosis of PID could be made, allowing clinicians to recognize that PID has many clinical presentations.

Future prospects focus primarily on the prevention of PID, since treatment does not prevent many of the long-term effects. Prevention involves continued widespread screening of asymptomatic men and women at risk for STDs, as well as partner referral and safer-sex education. Studies have shown that the screening and treatment of asymptomatic women for STDs has reduced the prevalence of these infections in the general population in the United States, thus translating into a reduction in the incidence of PID. With these prevention techniques, there is hope that the morbidity and serious sequelae of PID will be reduced.

Bibliography

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"Pelvic Inflammatory Disease (PID) Treatment." Centers for Disease Control and Prevention, March 1, 2013.

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