Pelvic Inflammatory Disease ✅

Related Subjects: |Ectopic Pregnancy | Ovarian Torsion | Ruptured Ovarian Cyst | Septic Abortion /Miscarriage | Pelvic Abscess | Acute Uterine Haemorrhage | Pelvic Inflammatory Disease

⚠️ Key exam pearl: Suspect pelvic inflammatory disease (PID) in any sexually active woman with lower abdominal or pelvic pain, especially with cervical motion tenderness, uterine tenderness, adnexal tenderness, abnormal vaginal discharge, intermenstrual/post-coital bleeding, deep dyspareunia or fever. Do a pregnancy test urgently to exclude ectopic pregnancy, and start empirical antibiotics if PID is clinically suspected - do not wait for swab results.

📖 Overview

• Definition: PID is infection and inflammation of the upper female genital tract, including endometritis, salpingitis, oophoritis, tubo-ovarian abscess and pelvic peritonitis.
• Cause: Usually ascending infection from the cervix or vagina. It is commonly sexually transmitted, but is often polymicrobial.
• Why it matters: Delayed treatment can cause tubal damage, subfertility, ectopic pregnancy, chronic pelvic pain and tubo-ovarian abscess.

🧬 Aetiology & Risk Factors

PID is often polymicrobial. Chlamydia trachomatis and Neisseria gonorrhoeae are important causes, but anaerobes and vaginal flora are also commonly involved.

• STIs: Chlamydia trachomatis, Neisseria gonorrhoeae, and sometimes Mycoplasma genitalium.
• Other organisms: anaerobes, Gardnerella vaginalis, streptococci, staphylococci and enteric Gram-negative organisms.
• Risk factors: age under 25, new sexual partner, multiple partners, previous STI, previous PID, recent instrumentation or termination, and IUCD insertion within the previous 3 weeks.

🤒 Clinical Presentation

• Common symptoms: Bilateral lower abdominal or pelvic pain, abnormal vaginal discharge, deep dyspareunia, intermenstrual bleeding or post-coital bleeding.
• Systemic features: Fever, malaise, nausea or vomiting may occur, especially in more severe disease.
• Examination: Lower abdominal tenderness, cervical motion tenderness, uterine tenderness, adnexal tenderness, adnexal mass or purulent cervical discharge.
• Important: Symptoms may be mild or non-specific, so maintain a low threshold for treatment if PID is suspected.

🚩 Red Flags / Admit or Urgently Refer

• Pregnancy or possible pregnancy
• Severe pain, severe systemic illness, sepsis or vomiting preventing oral treatment
• Suspected ectopic pregnancy, appendicitis, ovarian torsion or other surgical emergency
• Suspected tubo-ovarian abscess or pelvic mass
• Diagnostic uncertainty
• Failure to improve within 72 hours of starting antibiotics
• Inability to tolerate or adhere to outpatient treatment

🧾 Differential Diagnosis

• Ectopic pregnancy
• Acute appendicitis
• Ovarian torsion or ruptured ovarian cyst
• Urinary tract infection or pyelonephritis
• Endometriosis
• Gastroenteritis or inflammatory bowel disease flare

🔬 Investigations

• Pregnancy test: Essential in all women of reproductive age with pelvic pain.
• NAAT swabs: Endocervical or vulvovaginal swabs for chlamydia and gonorrhoea. Consider local testing for Mycoplasma genitalium if available or if symptoms persist.
• Sexual health screen: Offer testing for HIV and syphilis, and arrange full STI screening via sexual health services.
• Urine dip/culture: If urinary symptoms or UTI is in the differential.
• Bloods: FBC and CRP may support the diagnosis but normal inflammatory markers do not exclude PID.
• Imaging: Pelvic ultrasound if severe symptoms, suspected tubo-ovarian abscess, pelvic mass or diagnostic uncertainty.
• Laparoscopy: May help when diagnosis is uncertain, but treatment should not be delayed while awaiting definitive confirmation.

💊 NICE/UK Management

• Start empirical antibiotics promptly if PID is clinically suspected.
• First-line outpatient regimen:
  • Ceftriaxone 1 g IM stat PLUS
  • Doxycycline 100 mg orally twice daily for 14 days PLUS
  • Metronidazole 400 mg orally twice daily for 14 days
• Do not use doxycycline + metronidazole alone if ceftriaxone is indicated, because gonorrhoea cover is needed unless specialist advice says otherwise.
• Analgesia: Give appropriate pain relief, usually paracetamol and/or an NSAID if suitable.
• Sexual health referral: Refer or signpost to a sexual health clinic for full STI testing, partner notification and follow-up.
• Abstain from sex: Advise no sexual intercourse, including protected sex, until treatment is completed, symptoms have resolved, and partners have been treated.
• IUCD: Usually does not need immediate removal. Consider removal if symptoms do not improve within 72 hours, or seek specialist advice.

🏥 Inpatient Treatment

• Admit or arrange same-day gynaecology assessment if severe disease, pregnancy, suspected abscess, sepsis, vomiting, diagnostic uncertainty or failed outpatient therapy.
• IV antibiotic options should follow local antimicrobial policy or specialist advice.
• Suspected tubo-ovarian abscess may require IV antibiotics and drainage or surgery if large, ruptured or not improving.

👥 Partner Notification

• Current and recent sexual partners should be assessed, tested and treated according to sexual health guidance.
• Partner notification is essential to reduce reinfection and onward STI transmission.
• Male partners are commonly treated empirically for chlamydia unless test results or specialist advice indicate otherwise.

🔄 Follow-up

• Review within 72 hours to ensure symptoms are improving.
• If symptoms are not improving, reassess the diagnosis, adherence, antibiotic resistance, pregnancy status and the possibility of abscess or surgical pathology.
• Further review after treatment may be needed to confirm symptom resolution, swab results, partner management and contraception needs.

⚡ Complications

• Subfertility due to tubal scarring
• Ectopic pregnancy
• Chronic pelvic pain
• Recurrent PID
• Tubo-ovarian abscess
• Fitz-Hugh-Curtis syndrome: perihepatitis causing right upper quadrant pain

✅ Key Takeaways

PID is a clinical diagnosis and treatment should start promptly when suspected. The key safety step is to exclude pregnancy and ectopic pregnancy, then treat empirically with broad-spectrum antibiotics covering chlamydia, gonorrhoea and anaerobes. Sexual health referral, partner notification, abstinence advice and 72-hour review are crucial to prevent recurrence and long-term complications.

📚 References

• NICE CKS: Pelvic inflammatory disease
• BASHH: UK guideline for the management of pelvic inflammatory disease