Pathology

PID presents with a spectrum of inflammatory changes depending upon the severity of infection, and the frequency of episodes. These range from endometritis at one extreme to tubo-ovarian abscess, hydrosalpinx, pyosalpinx and pelvic peritonitis at the other. Chlamydial perihepatitis is called the Fitz-Hugh-Curtis syndrome.

Two sexually transmitted infections (Chlamydia trachomatis and Neisseria gonorrhoeae) have been strongly implicated in the aetiology of PID

• however, based on the pattern of organisms isolated from the upper genital tract, the infection may often be polymicrobial (caused by more than one type of bacteria)
  • this suggests that initial damage produced by C trachomatis or N gonorrhoeae may permit the opportunistic entry of other bacteria, including anaerobes
  • however, in many cases, no infection is found in the lower genital tract

Reference:

• Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR. Recommendations and Reports : Morbidity and Mortality Weekly Report
  2015;64(RR-03):1-137.
• Savaris RF et al. Antibiotic therapy for pelvic inflammatory disease. Cochrane Database of Systematic Reviews 2020, Issue 8. Art. No.: CD010285. DOI:0.1002/14651858.CD010285.pub3