Pelvic inflammatory disease (PID) is caused by a bacterial infection that spreads beyond the cervix to infect the upper female reproductive tract, including the uterus, fallopian tubes, ovaries, and surrounding tissue. The most common pathogens that cause PID are Chlamydia and Gonococci. Symptoms may vary considerably; while some women are asymptomatic, others may complain of mild pressure pain and discharge or present with signs of systemic inflammation, such as fever and severe abdominal pain. Diagnosis is based on clinical findings and may be supported by ultrasound, PCR, and/or cultures of cervical and urethral discharges. Calculated parenteral antibiotic therapy is indicated in women with suspected PID. Most common complications include infertility, ectopic pregnancy, and chronic pelvic pain.
- Pathogens 
- Risk factors 
- Pathophysiology: Infection from the lower genital tract (e.g., vagina, cervix) ascends to infect the upper reproductive tract (endometrium, fallopian tubes, ovaries) and/or peritoneal cavity.
- Possible sites of infection
Diagnosis is primarily based on clinical findings. Further diagnostic tests help confirm the diagnosis, especially in ambiguous cases.
- Important diagnostic criteria 
- Blood tests: : elevated ESR, leukocytosis
- Pregnancy test: to rule out an (ectopic) pregnancy
- Cervical and urethral swab
- Ultrasound: free fluid, abscesses, pyosalpinx/hydrosalpinx
- Exploratory laparoscopy 
- Endometrial biopsy: to confirm the presence of endometritis 
- Culdocentesis: aspiration of intraperitoneal fluid from the pouch of Douglas 
|Differential diagnosis of lower abdominal pain in women of reproductive age|
|Disorder||Clinical features||Diagnostic clues||Therapy|
|Ectopic pregnancy|| |
|Kidney stones|| |
|Ovarian cyst rupture|
|Pelvic cellulitis |
- Definition: inflammation of the uterine cervix
- Infectious (most common): C. trachomatis, N. gonorrhea, HSV-2 , T. vaginalis
- Young age
- Multiple sexual partners
- New sexual partner within the last 6 months
- Unprotected intercourse
- Often asymptomatic
- Usually no fever
- Vaginal discharge: may be purulent, blood-tinged, and/or malodorous
- Postcoital or intermenstrual bleeding
- Lower abdominal or pelvic pain
- Symptoms of the underlying condition (e.g., genital lesions in HSV infections)
- Physical examination
- Diagnosis mainly clinical 
- Further tests for identification of a pathogen
- Complications: PID
The differential diagnoses listed here are not exhaustive.
- Outpatient regimen
Inpatient regimen (parenteral antibiotics)
- Possible combinations (should be administered for 14 days)
- Switch to oral therapy with doxycycline after clinical improvement.
It is better to overtreat rather than delay treatment if PID is suspected.
- Pelvic peritonitis
- Fitz-Hugh-Curtis syndrome (perihepatitis)
- Tubo-ovarian abscess
- Infertility: caused by adnexitis, adhesions of the fallopian tubes and ovaries, and tubal scarring, which result in impaired ciliary function and tubal occlusion
- Ectopic pregnancy
- Chronic pelvic pain
- Hydrosalpinx/pyosalpinx: accumulation of fluid/pus in the fallopian tubes due to chronic inflammation and consequent stenosis
- Chronic salpingitis
We list the most important complications. The selection is not exhaustive.