Polymicrobial ascending infection of the upper female genital tract — empiric treatment with low threshold to prevent sequelae.
Also known as: PID, salpingitis, endometritis, tubo-ovarian abscess, TOA
Overview
Infection and inflammation of the upper female genital tract including any combination of endometritis, salpingitis, oophoritis, tubo-ovarian abscess, and pelvic peritonitis, typically caused by ascending sexually transmitted organisms.
Epidemiology
About 4.4% of sexually experienced US women aged 18–44 (~2.5 million) report a lifetime PID diagnosis (NHANES 2013–2014). Most common in sexually active women 15-25 years old. A major preventable cause of infertility, ectopic pregnancy, and chronic pelvic pain.
Try two board-style Pelvic Inflammatory Disease questions
Real questions from the FirstPassPA bank, with the full explanation. Pick an answer — no signup, no email.
Question 1ReproductiveMedium
A 26-year-old sexually active woman presents to the emergency department with 4 days of worsening right lower quadrant and pelvic pain, fever, and vaginal discharge. She has a history of chlamydial cervicitis. On examination temperature is 38.9°C, there is right adnexal and cervical motion tenderness, and a tender fullness is palpated in the right adnexa. Urine beta-hCG is negative and WBC is 18,000/mm3. Transvaginal ultrasound shows a 6 cm complex, thick-walled, multiloculated right adnexal mass. Which of the following is the most likely diagnosis?
ATubo-ovarian abscess
BOvarian cyst rupture
CAcute appendicitis
DOvarian torsion
ERuptured ectopic pregnancy
Reveal answer & full explanation
Correct answer: A — Tubo-ovarian abscess
ATubo-ovarian abscess✓
BOvarian cyst rupture
CAcute appendicitis
DOvarian torsion
ERuptured ectopic pregnancy
Why Tubo-ovarian abscess is correct
Tubo-ovarian abscess is a complication of ascending pelvic inflammatory disease; the prior chlamydial infection, fever, cervical motion and adnexal tenderness, and leukocytosis establish the infectious picture.
The discriminating finding is a complex, thick-walled, multiloculated adnexal mass on ultrasound, representing the walled-off abscess.
Management is inpatient broad-spectrum IV antibiotics (such as cefotetan or cefoxitin plus doxycycline, or clindamycin plus gentamicin), with drainage for large abscesses, rupture, or failure to improve within 48-72 hours.
Why the others are wrong
Ovarian cyst rupture — causes sudden unilateral pain and may show free fluid, but it does not produce sustained fever, marked leukocytosis, and a thick-walled multiloculated mass (anchoring on acute adnexal pain).
Ovarian torsion — presents with abrupt severe pain, nausea, and an enlarged edematous ovary with reduced Doppler flow, not a thick-walled abscess with high fever and a PID history (premature closure on the most time-critical adnexal emergency).
Ruptured ectopic pregnancy — is excluded by the negative beta-hCG; it would present with a positive pregnancy test, an empty uterus, and hemoperitoneum (buzzword-matching on adnexal mass plus pain).
Acute appendicitis — right lower quadrant pain, fever, and leukocytosis fit appendicitis, but the prior chlamydial infection, cervical motion and adnexal tenderness, and a thick-walled multiloculated adnexal mass localize the process to the adnexa; appendicitis would typically show a noncompressible, dilated appendix rather than a complex adnexal mass (premature closure on the most common surgical cause of RLQ pain).
Question 2ReproductiveMedium
A 24-year-old sexually active woman presents with several days of lower abdominal pain and mucopurulent cervical discharge. She is not pregnant and has no intrauterine device. On pelvic examination there is cervical motion tenderness and bilateral adnexal tenderness, and her temperature is 38.1 C (100.6 F). Which of the following is the most likely diagnosis?
ACandidal vaginitis
BPelvic inflammatory disease
CTrichomoniasis
DBacterial vaginosis
EMucopurulent cervicitis
Reveal answer & full explanation
Correct answer: B — Pelvic inflammatory disease
ACandidal vaginitis
BPelvic inflammatory disease✓
CTrichomoniasis
DBacterial vaginosis
EMucopurulent cervicitis
Why Pelvic inflammatory disease is correct
Pelvic inflammatory disease (PID) is a clinical diagnosis in a sexually active woman with pelvic or lower abdominal pain plus at least one of: cervical motion tenderness, uterine tenderness, or adnexal tenderness
This patient has cervical motion tenderness, bilateral adnexal tenderness, mucopurulent cervical discharge, and fever, indicating ascending genital tract infection
Empiric treatment is started on clinical grounds to prevent tubal damage; per current CDC guidance the outpatient regimen is ceftriaxone IM plus doxycycline plus metronidazole
Why the others are wrong
Bacterial vaginosis — thin gray discharge with a fishy odor and no cervical motion tenderness, adnexal tenderness, or fever; choosing it is buzzword-matching on vaginal discharge while ignoring the upper-tract signs
Candidal vaginitis — thick white discharge and vulvovaginal pruritus without cervical motion or adnexal tenderness; premature closure on a common vaginitis
Trichomoniasis — frothy discharge and possible cervicitis, but it does not produce bilateral adnexal and cervical motion tenderness with fever; anchoring on discharge alone misses the upper-tract findings
Mucopurulent cervicitis — the mucopurulent cervical discharge fits, which is why it tempts, but cervicitis is a lower-tract infection and does not account for the cervical motion tenderness, bilateral adnexal tenderness, and fever, which mark ascending spread; stopping at the cervix is premature closure that undertreats an infection needing the PID regimen
That's 2. Get 7,700+ more.
Unlock the full FirstPassPA bank: 7,700+ board-style questions, flashcards, and an AI tutor that explains every answer. Your 7-day free trial includes everything, and there's no credit card required.
You've read your 2 free diagnosis previews. Create your free account to unlock the full Pelvic Inflammatory Disease (PID) outline — plus all 514 diagnoses, 7,700+ board-style questions, flashcards, and an AI tutor. Your 7-day free trial includes everything, and there's no credit card required.
Prior PID or STI (especially gonorrhea or chlamydia)
Inconsistent barrier contraception
Intrauterine procedure within 3 weeks (IUD insertion, endometrial biopsy)
Bacterial vaginosis
Pathophysiology
Cervical pathogens (Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium) ascend through the endocervical canal to the upper tract, disrupting the cervical mucus barrier. Subsequent polymicrobial infection with anaerobes (Bacteroides, Peptostreptococcus), aerobes (E. coli, streptococci), and genital tract flora produces tubal inflammation, abscess formation, and scarring.
Clinical presentation
Symptoms
Lower abdominal/pelvic pain (often bilateral)
Abnormal vaginal discharge
Intermenstrual or postcoital bleeding
Dyspareunia
Fever, chills, nausea (variable)
Many cases are mild or subclinical — silent PID
Signs / physical exam
Cervical motion tenderness, uterine tenderness, or adnexal tenderness on bimanual exam
Mucopurulent cervical discharge or friability
Fever >38.3°C (101°F)
Right upper quadrant tenderness suggests Fitz-Hugh-Curtis syndrome (perihepatitis)
Classic findings
Sexually active young woman with bilateral lower abdominal pain, cervical motion tenderness, and mucopurulent cervical discharge.
Differential diagnosis
Ectopic pregnancy — Always check hCG; unilateral pain, vaginal bleeding, possible adnexal mass
Appendicitis — RLQ migration, anorexia, McBurney point tenderness; CT scan
Ovarian torsion — Sudden severe unilateral pain, nausea/vomiting; Doppler ultrasound
Ruptured ovarian cyst — Sudden pain, may have small free fluid; ultrasound
CDC minimum criteria (initiate empiric therapy if any one is present in a sexually active young woman with pelvic pain and no other cause): cervical motion tenderness, uterine tenderness, OR adnexal tenderness. Additional supportive criteria: oral temperature >38.3°C, abnormal cervical discharge, leukocytes on wet mount, elevated ESR/CRP, lab-confirmed GC or chlamydia.
Labs
Pregnancy test
Nucleic acid amplification tests for Neisseria gonorrhoeae and Chlamydia trachomatis (cervical or urine)
Wet mount of vaginal secretions: abundant leukocytes support PID (normal cervical discharge with no WBCs makes PID unlikely); also identifies BV/trichomonas
HIV and syphilis testing
CBC (leukocytosis), CRP/ESR (elevated)
Urinalysis
Imaging
Transvaginal ultrasound — if TOA suspected (severe pain, palpable mass, systemic illness, or no response to therapy)
CT scan — alternative diagnosis (appendicitis) or complicated disease
Laparoscopy — gold standard but rarely required; reserved for diagnostic uncertainty or failed therapy
Diagnostic algorithm
flowchart TD
A[Sexually active woman<br/>with pelvic pain] --> B[hCG, pelvic exam,<br/>GC/CT, urinalysis]
B --> C{CMT, uterine, or<br/>adnexal tenderness?}
C -->|Yes| D[Empiric PID treatment]
D --> E{Inpatient criteria?<br/>Pregnancy, TOA, severe,<br/>cannot tolerate PO}
E -->|No| F[Outpatient: ceftriaxone IM<br/>+ doxycycline + metronidazole<br/>× 14 days]
E -->|Yes| G[Inpatient IV antibiotics]
G --> H[Pelvic ultrasound:<br/>TOA?]
H -->|Yes| I[IV abx ± drainage<br/>if >7 cm or refractory]
F --> J[Reassess 48-72 h]
J -->|Improving| K[Complete 14-d course<br/>treat partners<br/>retest at 3 mo]
J -->|Not improving| L[Hospitalize, image,<br/>reconsider diagnosis]
PID management pathway — low threshold to treat empirically; escalate based on severity.
Treatment
First-line
Outpatient regimen (CDC 2021): ceftriaxone 500 mg IM × 1 + doxycycline 100 mg PO BID × 14 days + metronidazole 500 mg PO BID × 14 days
Inpatient indications: pregnancy, severe illness, TOA, failure of outpatient therapy, inability to tolerate PO, surgical emergency cannot be excluded
Inpatient regimen: ceftriaxone 1 g IV q24h + doxycycline 100 mg PO/IV q12h + metronidazole 500 mg PO/IV q12h; OR cefoxitin 2 g IV q6h or cefotetan 2 g IV q12h PLUS doxycycline 100 mg IV/PO q12h (transition to oral doxycycline + metronidazole × 14 days total)
Alternative IV: clindamycin + gentamicin (especially for TOA)
Tubo-ovarian abscess
IV antibiotics with anaerobic coverage (clindamycin + gentamicin or ampicillin-sulbactam + doxycycline)
Image-guided drainage if abscess >7-9 cm, no response in 48-72 h, or clinical deterioration
Surgical drainage/oophorectomy if rupture suspected (acute abdomen, sepsis)
Pregnancy
Hospitalize
IV antibiotics; avoid doxycycline if possible — use azithromycin alternative
Maternal-fetal medicine and infectious disease consultation
Second-line / adjunct
Treat all sexual partners from previous 60 days for GC/CT
Abstinence until both treated and asymptomatic
Re-test for GC/CT 3 months after treatment (high re-infection rate)
Do NOT routinely remove IUD — leave in place if clinically improving
Complications
Infertility (12% after first episode, ~50% after three)
Ectopic pregnancy (6-10x risk)
Chronic pelvic pain
Tubo-ovarian abscess and rupture (life-threatening)
Brunham NEJM 2015 — Brunham RC, Gottlieb SL, Paavonen J. Pelvic Inflammatory Disease. N Engl J Med 2015;372(21):2039-2048
ACOG PB 186 — ACOG Practice Bulletin No. 186: Long-Acting Reversible Contraception: Implants and Intrauterine Devices (Obstet Gynecol 2017;130(5):e251-e269)
MMWR 2017 — Kreisel K et al. Prevalence of Pelvic Inflammatory Disease in Sexually Experienced Women of Reproductive Age — United States, 2013–2014. MMWR Morb Mortal Wkly Rep 2017;66(3):80-83
Practice Reproductive questions on FirstPassPA
Turn this outline into retention. 7,700+ board-style questions with an AI tutor that explains every answer — free to start, no card required.
Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA or PAEA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants; End of Rotation™ is a program of the Physician Assistant Education Association.