Experimental pain tolerance is decreased and independent of clinical pain intensity in patients with endometriosis

OBJECTIVE: To investigate alterations in tactile, pain thresholds and pain tolerance thresholds in patients with endometriosis using a multimodality approach. DESIGN: Cross-sectional study. SETTING: Multidisciplinary referral center. PATIENT(S): Women with proven endometriosis (N = 35) and healthy controls (N = 38). INTERVENTION(S): Pain processing was tested using quantitative sensory testing (QST) to investigate sensation, pain, and pain tolerance thresholds for thermal, electrical, and pressure stimuli. MAIN OUTCOME MEASURE(S): Differences in QST measures in patients with endometriosis and in healthy controls on the endometriosis site and control sites, and the association between QST outcomes and patient characteristics. RESULT(S): We observed a significantly decreased pain tolerance in patients with endometriosis, independent of clinical pain intensity or revised American Society for Reproductive Medicine stage, compared with healthy controls. CONCLUSION(S): Increasing knowledge concerning mechanisms underlying the pain of women with endometriosis creates opportunities to develop new treatment options. More attention should be paid not only to treat endometriosis in a surgical or pharmacologic way, but also to desensitize by pain education or cognitive therapy.