Pelvic inflammatory disease vs Ovarian torsion
How to tell Pelvic inflammatory disease and Ovarian torsion apart when a board question makes them look alike.
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Sudden unilateral pelvic pain with vomiting and an enlarged ovary on ultrasound points to ovarian torsion.
Side by side
Subacute bilateral lower abdominal pain with cervical motion tenderness, uterine or adnexal tenderness, fever, and STI risk supports pelvic inflammatory disease.
Sudden severe unilateral pelvic pain with nausea or vomiting and adnexal tenderness suggests ovarian torsion requiring urgent surgery.
Ascending polymicrobial genital tract infection inflames endometrium, tubes, and adnexa.
Twisting of the ovarian vascular pedicle causes venous and then arterial compromise leading to ovarian ischemia.
PID diagnosis is clinical with pelvic pain plus cervical motion, uterine, or adnexal tenderness; supportive findings include temperature above 38.3 C, WBC above 10000/uL, elevated ESR or CRP, and positive gonorrhea or chlamydia testing.
Torsion is suggested by unilateral enlarged edematous ovary over 4 cm with peripheral follicles on ultrasound and absent or reduced venous flow on Doppler, although intermittent flow can persist early.
The trap
Empiric PID treatment can delay salvage when torsion is the true diagnosis. The resolving clue is abrupt unilateral onset with nausea and adnexal mass, which should trigger immediate gynecologic surgical evaluation rather than outpatient antibiotic trial.
The repair move
Next best step: obtain urgent transvaginal ultrasound with Doppler and call gynecologic surgery immediately for suspected torsion, proceeding to prompt diagnostic laparoscopy with detorsion; if exam instead supports PID, start ceftriaxone 500 mg IM once plus doxycycline 100 mg orally twice daily for 14 days with metronidazole 500 mg orally twice daily for 14 days.
Try a free question
CoreA 23-year-old woman has sudden left pelvic pain and vomiting for 2 hours. Pelvic ultrasound shows a 7 cm enlarged left ovary with peripheral follicles. What is the most likely diagnosis?
Show answer and explanation
Answer: B. Ovarian torsion. Abrupt unilateral pain with vomiting and enlarged ovary on ultrasound is classic for ovarian torsion.
Why the other choices are tempting
- A. Wrong because PID is usually more subacute with infectious and cervical motion tenderness features.
- C. Wrong because endometriosis pain is recurrent and cyclic, not usually this abrupt ischemic presentation.
- D. Wrong because mittelschmerz is transient ovulatory pain without enlarged ischemic ovary findings.
- E. Wrong because ectopic rupture would usually involve positive pregnancy testing and intraperitoneal bleeding signs.
Flashcards
Tap a card to flip it.
What symptom tempo most strongly favors ovarian torsion over PID?
Abrupt severe unilateral pain with nausea and vomiting favors ovarian torsion.
What pelvic exam finding is classically required to support PID diagnosis?
Cervical motion tenderness, uterine tenderness, or adnexal tenderness in the appropriate clinical setting.
Quick answers
What is the fastest way to tell Pelvic inflammatory disease from Ovarian torsion?
Sudden unilateral pelvic pain with vomiting and an enlarged ovary on ultrasound points to ovarian torsion.
What is the key clue for Pelvic inflammatory disease?
Subacute bilateral lower abdominal pain with cervical motion tenderness, uterine or adnexal tenderness, fever, and STI risk supports pelvic inflammatory disease.
What is the key clue for Ovarian torsion?
Sudden severe unilateral pelvic pain with nausea or vomiting and adnexal tenderness suggests ovarian torsion requiring urgent surgery.
What is the common trap with Pelvic inflammatory disease vs Ovarian torsion?
Empiric PID treatment can delay salvage when torsion is the true diagnosis. The resolving clue is abrupt unilateral onset with nausea and adnexal mass, which should trigger immediate gynecologic surgical evaluation rather than outpatient antibiotic trial.