Chronic pelvic inflammatory disease (PID) is characterized by persistent inflammation of the female reproductive organs, leading to fibrosis and scarring. This results in chronic pelvic pain, which is the hallmark symptom distinguishing chronic PID from its acute form. Unlike acute PID, chronic PID does not typically present with systemic signs like fever or sudden severe symptoms such as vomiting. The pain is often dull and persistent, reflecting ongoing tissue damage and adhesions. Early recognition of chronic pelvic pain in PID is crucial to prevent further complications such as infertility or ectopic pregnancy.

Reference: Williams Gynecology, Hoffman et al., 3rd Edition.