Psychoneuroimmunology of Pelvic Pain

Chronic Pelvic Pain (CPP) is pain lasting over three months, classified as a biopsychosocial disorder in ICD-11. Endometriosis and interstitial cystitis/bladder pain syndrome (IC/BPS) cause CPP, linking to depression and poor life quality. The Psychoneuroimmunological (PNI) model explains CPP's involvement with immune, nervous, and psychological systems. In endometriosis, ectopic implants trigger immune cell infiltration, increasing cytokines and NGF. IC/BPS shows inflammation with immune infiltration causing sensitization. Inflammatory signals activate microglia and astrocytes, triggering neuroinflammation. Stress affects the HPA axis, reducing anti-inflammatory responses and activating NLRP3 inflammasome. The gut-brain axis links dysbiosis to inflammation, while epigenetic mechanisms maintain neuronal hyperexcitability. Treatment must target the neuroimmune axis through pharmacologic and behavioral therapy for outcomes.