⚕️
Reproductive · Clinical Topics
Pelvic Inflammatory Disease
Pelvic Inflammatory Disease (PID) is an infection of the upper female genital tract. It's a critical diagnosis in young, sexually active women due to its significant long-term sequelae: chronic pelvic pain, ectopic pregnancy, and tubal factor infertility. Early empirical antibiotic treatment is key.
📌 Learning Objectives
- Describe the pathophysiology of Pelvic Inflammatory Disease (PID) and its common causative organisms.
- Identify the key clinical features and diagnostic criteria for PID.
- Explain the rationale for prompt empirical antibiotic treatment in suspected PID.
- Discuss the major long-term complications of PID, including infertility and ectopic pregnancy.
- Outline the management principles for PID, including partner notification and treatment.
- Differentiate PID from other causes of acute pelvic pain in women.
📋 Overview
PID is an ascending infection from the lower genital tract (vagina/cervix) to the uterus, fallopian tubes (salpingitis), and ovaries. It's a common cause of acute pelvic pain in sexually active women, particularly those aged 15-24. The most common culprits are STIs, primarily *Chlamydia trachomatis* and *Neisseria gonorrhoeae*, but it can also be polymicrobial. Due to the high risk of serious complications like tubal infertility (up to 10-20% after one episode, increasing with recurrence) and ectopic pregnancy (6-10 times higher risk), UK guidelines (NICE, BASHH) advocate for a low threshold for empirical antibiotic treatment based on clinical suspicion, even before definitive microbiological results.
🔬 Basic Science
PID typically starts as cervicitis, with pathogens ascending through the cervical canal (which is more permeable during menstruation). The infection spreads to the endometrium (endometritis) and then to the fallopian tubes (salpingitis). Inflammation in the tubes leads to oedema, exudate, and ultimately fibrosis. This scarring damages the ciliated epithelium and narrows the lumen, impairing ovum transport and increasing the risk of both infertility and ectopic pregnancy. Severe infection can lead to a tubo-ovarian abscess (TOA). Spread to the pelvic peritoneum causes peritonitis, and if it tracks along the paracolic gutters to the liver capsule, it causes perihepatitis (Fitz-Hugh-Curtis syndrome).
🏥 Clinical Relevance
Presentations vary from asymptomatic to severe sepsis. Common symptoms include bilateral lower abdominal pain (often dull ache, worse with movement or intercourse), deep dyspareunia, abnormal vaginal discharge (purulent, offensive), intermenstrual or post-coital bleeding, and sometimes fever, nausea, or vomiting. On examination, look for lower abdominal tenderness, adnexal tenderness, and the pathognomonic cervical excitation (pain on moving the cervix during bimanual exam). Red flags for admission include pregnancy, severe symptoms, suspected TOA, or failure of outpatient treatment. Differentials include ectopic pregnancy, appendicitis, ovarian torsion, UTI, and endometriosis.
🧪 Investigations
1. **Bedside:**
- **Pregnancy test:** *Crucial* to rule out ectopic pregnancy.
- **Urinalysis:** To rule out UTI.
2. **Microbiology:**
- **Endocervical/High Vaginal Swabs (NAAT):** For *Chlamydia trachomatis*, *Neisseria gonorrhoeae*, and *Mycoplasma genitalium*. Do *not* delay treatment awaiting results.
3. **Bloods:**
- **FBC, CRP, ESR:** Inflammatory markers may be raised but can be normal in mild PID.
4. **Imaging:**
- **Transvaginal Ultrasound (TVUS):** Indicated if diagnosis is uncertain, to rule out other pathology (e.g., ectopic pregnancy, ovarian cyst), or to identify a tubo-ovarian abscess (TOA).
5. **Laparoscopy:** Gold standard for diagnosis (visualises inflamed tubes, adhesions) but rarely performed unless diagnosis is unclear or treatment fails.
- **Pregnancy test:** *Crucial* to rule out ectopic pregnancy.
- **Urinalysis:** To rule out UTI.
2. **Microbiology:**
- **Endocervical/High Vaginal Swabs (NAAT):** For *Chlamydia trachomatis*, *Neisseria gonorrhoeae*, and *Mycoplasma genitalium*. Do *not* delay treatment awaiting results.
3. **Bloods:**
- **FBC, CRP, ESR:** Inflammatory markers may be raised but can be normal in mild PID.
4. **Imaging:**
- **Transvaginal Ultrasound (TVUS):** Indicated if diagnosis is uncertain, to rule out other pathology (e.g., ectopic pregnancy, ovarian cyst), or to identify a tubo-ovarian abscess (TOA).
5. **Laparoscopy:** Gold standard for diagnosis (visualises inflamed tubes, adhesions) but rarely performed unless diagnosis is unclear or treatment fails.
💊 Management
Prompt empirical antibiotic treatment is essential to prevent long-term complications.
**Outpatient Regimen (BASHH/NICE guidelines):**
- **IM Ceftriaxone 1g (single dose):** Covers gonorrhoea.
- **Oral Doxycycline 100mg BD for 14 days:** Covers chlamydia and other bacteria.
- **Oral Metronidazole 400mg BD for 14 days:** Covers anaerobes.
**Indications for Hospital Admission:**
- Pregnancy
- Severe clinical illness (e.g., high fever, systemic signs of sepsis)
- Suspected tubo-ovarian abscess
- Failure to respond to oral antibiotics within 72 hours
- Diagnostic uncertainty where surgical intervention (e.g., laparoscopy) may be needed.
**Partner Management:** All sexual partners from the last 6 months should be contacted, screened, and empirically treated for STIs. Advise no unprotected intercourse until both patient and partners have completed treatment and symptoms have resolved.
**Outpatient Regimen (BASHH/NICE guidelines):**
- **IM Ceftriaxone 1g (single dose):** Covers gonorrhoea.
- **Oral Doxycycline 100mg BD for 14 days:** Covers chlamydia and other bacteria.
- **Oral Metronidazole 400mg BD for 14 days:** Covers anaerobes.
**Indications for Hospital Admission:**
- Pregnancy
- Severe clinical illness (e.g., high fever, systemic signs of sepsis)
- Suspected tubo-ovarian abscess
- Failure to respond to oral antibiotics within 72 hours
- Diagnostic uncertainty where surgical intervention (e.g., laparoscopy) may be needed.
**Partner Management:** All sexual partners from the last 6 months should be contacted, screened, and empirically treated for STIs. Advise no unprotected intercourse until both patient and partners have completed treatment and symptoms have resolved.
Revision Resources – expand the sections below for high-yield notes, exam pearls, key facts and further reading.
MLA High-Yield Notes & Quick Revision ⌄
1. **SBA Trap:** Always consider PID in a young, sexually active woman presenting with lower abdominal pain, even if symptoms are mild. The long-term consequences are severe.
2. **OSCE Pearl:** When performing a bimanual exam, demonstrate cervical excitation clearly. Explain to the examiner that this sign, along with adnexal tenderness, is highly suggestive of PID.
3. **Viva Question:** "What are the long-term complications of PID?" (Answer: Infertility, ectopic pregnancy, chronic pelvic pain, recurrent PID).
4. **Common Misconception:** That PID always presents with a high fever and severe symptoms. Many cases are subclinical or mild, yet still cause significant tubal damage.
5. **Must-Know Association:** Fitz-Hugh-Curtis syndrome (perihepatitis) with PID, presenting with right upper quadrant pain and shoulder tip pain due to diaphragmatic irritation.
6. **Management Pearl:** Do *not* wait for swab results to start antibiotics if clinical suspicion is high. Empirical treatment is key.
2. **OSCE Pearl:** When performing a bimanual exam, demonstrate cervical excitation clearly. Explain to the examiner that this sign, along with adnexal tenderness, is highly suggestive of PID.
3. **Viva Question:** "What are the long-term complications of PID?" (Answer: Infertility, ectopic pregnancy, chronic pelvic pain, recurrent PID).
4. **Common Misconception:** That PID always presents with a high fever and severe symptoms. Many cases are subclinical or mild, yet still cause significant tubal damage.
5. **Must-Know Association:** Fitz-Hugh-Curtis syndrome (perihepatitis) with PID, presenting with right upper quadrant pain and shoulder tip pain due to diaphragmatic irritation.
6. **Management Pearl:** Do *not* wait for swab results to start antibiotics if clinical suspicion is high. Empirical treatment is key.
Acute Pelvic Pain in Women
Abnormal Vaginal Discharge
Infertility
Ectopic Pregnancy
Sexually Transmitted Infections
Chronic Pelvic Pain
- PID is an infection of the upper female genital tract.
- Most common causes are *Chlamydia trachomatis* and *Neisseria gonorrhoeae*.
- Key clinical sign: cervical excitation on bimanual exam.
- Long-term complications: infertility, ectopic pregnancy, chronic pelvic pain.
- Empirical antibiotics (Ceftriaxone, Doxycycline, Metronidazole) are started promptly.
- Partner notification and treatment are essential.
Exam Pearls ⌄
⭐ High Yield
PID is an ascending infection of the upper female genital tract, primarily caused by STIs like *Chlamydia trachomatis*.
Cervical excitation (Chandelier sign) on bimanual examination is a key clinical sign.
Major long-term complications include tubal infertility, ectopic pregnancy, and chronic pelvic pain.
Empirical broad-spectrum antibiotics must be started promptly based on clinical suspicion, without waiting for swab results.
Fitz-Hugh-Curtis syndrome (perihepatitis) is a complication presenting with right upper quadrant pain.
Partner notification, screening, and empirical treatment are crucial to prevent re-infection.
Risk factors include multiple sexual partners, lack of barrier contraception, and previous STIs.
Transvaginal ultrasound is indicated if the diagnosis is uncertain or to rule out a tubo-ovarian abscess.
💡 Clinical Pearl
Ectopic Pregnancy: PID significantly increases the risk of ectopic pregnancy due to tubal damage and scarring.
Urinary Tract Infection: Can be a differential diagnosis for lower abdominal pain; urinalysis helps differentiate.
Appendicitis: Acute appendicitis can mimic PID, especially with right-sided pain; imaging may be needed to differentiate.
Ovarian Torsion: Causes sudden, severe unilateral pelvic pain; TVUS is crucial for diagnosis.
Endometriosis: Causes chronic pelvic pain and dyspareunia, but typically has a more chronic course than acute PID.
Sepsis: Severe PID can lead to systemic sepsis, requiring hospital admission and IV antibiotics.
⚠️ Exam Tip — Common Mistakes
Delaying antibiotic treatment while awaiting swab results.
Underestimating the severity of long-term complications, even with mild initial symptoms.
Failing to consider PID in women presenting with atypical symptoms or without overt discharge.
Not treating sexual partners, leading to re-infection.
Confusing PID symptoms with other abdominal or urinary conditions without proper investigation.
Assuming PID always presents with a high fever or severe systemic symptoms.
Key Facts ⌄
Most common cause: *Chlamydia trachomatis*.
Key clinical sign: Cervical excitation (Chandelier sign) on bimanual examination.
Major long-term complications: Tubal infertility and ectopic pregnancy.
Fitz-Hugh-Curtis syndrome: Perihepatitis with 'violin-string' adhesions, causing right upper quadrant pain.
Empirical antibiotics must be started promptly based on clinical suspicion.
Partner notification and treatment are crucial to prevent re-infection.
Risk factors include multiple sexual partners, lack of barrier contraception, previous STIs, and recent IUD insertion (first 20 days).
Related Topics ⌄
References ⌄
- BASHH UK National Guideline for the Management of Pelvic Inflammatory Disease
- NICE CKS - Pelvic inflammatory disease
- BNF
Further Resources
Medical Portfolio & Career Development
Build a professional portfolio website for applications, audits, teaching, research and career progression.
CVtoWebsite.com →