Pelvic inflammatory disease
Pelvic inflammatory disease is infection ascending from the lower genital tract into the uterus, fallopian tubes and adjacent structures, where the resulting inflammation and scarring (not the initial infection itself) cause its long-term morbidity.
In a nutshell
PID is ascending infection from the lower genital tract into the uterus, tubes and pelvis, most often gonococcal, chlamydial or polymicrobial. The tube's inflamed, poorly regenerating epithelium heals by scarring, which is the mechanism behind chronic pain, infertility and ectopic pregnancy, hence the low threshold for early, broad, empirical treatment.
Classic presentation
A young sexually active woman with bilateral lower abdominal pain, deep dyspareunia, abnormal discharge and cervical motion tenderness on examination.
Key points
- PID is a syndrome of ascent, not a single organism: treatment must be broad-spectrum, covering gonorrhoea, chlamydia and anaerobes.
- Tubal damage heals by fibrosis, not regeneration, which is the mechanism linking PID to chronic pelvic pain, subfertility and ectopic pregnancy.
- Diagnosis is clinical: no single test is sensitive or specific enough, so a low threshold to start empirical antibiotics is standard practice.
- A negative chlamydia/gonorrhoea swab does not exclude PID.
- Always exclude pregnancy, since ectopic pregnancy is a key differential and changes management.
- Fitz-Hugh-Curtis syndrome (right upper quadrant pain from perihepatic adhesions) reflects how far ascending infection can spread.
First-line investigation
Pregnancy test to exclude ectopic pregnancy, alongside NAAT swabs for chlamydia and gonorrhoea, but diagnosis and treatment should not wait for results.
First-line management
Empirical broad-spectrum antibiotics covering gonorrhoea, chlamydia and anaerobes, started promptly on clinical suspicion.
Exam traps
- Waiting for swab results before starting antibiotics is wrong: delay increases tubal damage, so treatment is empirical.
- A negative NAAT swab does not rule out PID; the diagnosis remains clinical.
- Right upper quadrant pain in a woman with pelvic pain may be Fitz-Hugh-Curtis syndrome, not gallbladder disease.
Educational content pending clinical review. Not medical advice.