Pelvic Inflammatory Disease (PID)

Definition | Aetiology | Risk Factors | Clinical Presentation | Investigations | Management | When to Refer | References

Definition

Pelvic Inflammatory Disease (PID) is an infection of the upper female genital tract, including the uterus, fallopian tubes, and ovaries. It often results from sexually transmitted infections (STIs) and can lead to severe complications, such as infertility, chronic pelvic pain, and ectopic pregnancy if not promptly treated.

Aetiology

PID typically occurs when bacteria ascend from the lower genital tract (vagina and cervix) to the upper genital tract. The most common pathogens involved are:

• Chlamydia trachomatis: A leading cause of PID, often asymptomatic in its initial stages.
• Neisseria gonorrhoeae: Another common STI associated with PID, though its prevalence has declined in recent years.
• Mycoplasma genitalium: Increasingly recognised as a contributor to PID.
• Polymicrobial Infections: In many cases, PID is caused by a mixture of aerobic and anaerobic bacteria, including organisms from the normal vaginal flora.

Risk Factors

Several factors increase the risk of developing PID:

• Multiple Sexual Partners: Increases the likelihood of contracting STIs.
• Previous PID: A history of PID increases the risk of recurrence.
• Age: Women under 25 years are at higher risk, particularly those who are sexually active.
• Unprotected Sex: Increases the risk of acquiring STIs that can lead to PID.
• Recent Intrauterine Device (IUD) Insertion: Slightly increases the risk of PID shortly after insertion, although the overall risk is low.
• History of STIs: A history of chlamydia, gonorrhoea, or other STIs increases the risk of PID.

Clinical Presentation

PID can present with a range of symptoms, which can vary in severity. Common symptoms include:

• Lower Abdominal Pain: The most common symptom, often bilateral and dull or crampy in nature.
• Abnormal Vaginal Discharge: May be purulent or have an unusual odour.
• Fever: A low-grade fever is common, though high fever may indicate severe infection.
• Dyspareunia: Pain during sexual intercourse.
• Abnormal Uterine Bleeding: Includes intermenstrual bleeding or post-coital bleeding.
• Dysuria: Painful urination, often due to concurrent lower urinary tract infection.
• Right Upper Quadrant Pain: In cases of Fitz-Hugh-Curtis syndrome, where the infection spreads to the liver capsule.

Investigations

The diagnosis of PID is primarily clinical, but the following investigations can support the diagnosis and rule out other conditions:

• Pelvic Examination: To assess for cervical motion tenderness, uterine tenderness, and adnexal tenderness, which are hallmark signs of PID.
• Cervical Swabs: For chlamydia, gonorrhoea, and Mycoplasma genitalium to identify the causative pathogen.
• Full Blood Count (FBC): May show elevated white blood cell count, indicating infection or inflammation.
• C-Reactive Protein (CRP): Often elevated in cases of PID but is a non-specific marker of inflammation.
• Ultrasound: Can help rule out other conditions such as ectopic pregnancy or ovarian cysts, and may show tubo-ovarian abscesses in severe PID.
• Pregnancy Test: Essential to rule out ectopic pregnancy in women of reproductive age presenting with abdominal pain.

Management

Prompt treatment of PID is essential to prevent complications. Management typically involves a combination of antibiotic therapy and patient education:

Antibiotic Therapy

• Outpatient Treatment: For mild to moderate cases, oral antibiotics such as doxycycline (100 mg twice daily for 14 days) and metronidazole (400 mg twice daily for 14 days) are commonly used, often in combination with a single dose of intramuscular ceftriaxone (500 mg).
• Inpatient Treatment: Severe cases or those not responding to oral antibiotics may require hospital admission for intravenous antibiotics, such as ceftriaxone combined with metronidazole and doxycycline.

Supportive Care

• Pain Management: NSAIDs such as ibuprofen can be used to manage pain.
• Partner Notification and Treatment: Sexual partners should be notified, tested, and treated to prevent reinfection.
• Follow-Up: Review the patient within 48-72 hours to ensure clinical improvement, and follow up to confirm resolution of symptoms.
• Education: Educate the patient on safe sex practices, the importance of completing the antibiotic course, and the need to avoid sexual intercourse until treatment is completed and symptoms have resolved.

When to Refer

Referral to secondary care or a gynaecologist is warranted in the following situations:

• Severe cases of PID requiring intravenous antibiotics or if the patient is not responding to outpatient treatment.
• Suspected tubo-ovarian abscess, which may require surgical intervention.
• If the diagnosis is unclear or if there is suspicion of an alternative diagnosis such as ectopic pregnancy or appendicitis.
• In cases of recurrent PID, for further evaluation and management to prevent long-term complications.

References

1. NHS (2024) Pelvic Inflammatory Disease (PID). Available at: https://www.nhs.uk/conditions/pelvic-inflammatory-disease-pid/ (Accessed: 26 August 2024).
2. National Institute for Health and Care Excellence (2024) Pelvic Inflammatory Disease: Diagnosis and Management. Available at: https://www.nice.org.uk/guidance/ng151 (Accessed: 26 August 2024).
3. British Medical Journal (2024) Pelvic Inflammatory Disease: Clinical Review. Available at: https://www.bmj.com/content/350/bmj.g990 (Accessed: 26 August 2024).

Back to Top