The Significance of Cutaneous Allodynia in a Woman With Chronic Pelvic Pain.

BACKGROUND

This is a case report of sensory assessment in a woman with severe chronic pelvic pain following uterine artery embolization, and a discussion of a commonly observed sensory manifestation (allodynia) associated with chronic pelvic pain due to gynaecological conditions. Allodynia, as a common sensory abnormality can be readily detected at the bedside and represents the development of pain sensitization. Emergence of abdominal and perineal allodynia (assessed by cotton swap stroking and/or questionnaire) is associated with the development of the clinical features of sensitization: continuous pelvic pain, muscle tenderness, and reduced pressure pain thresholds.

METHODS

A uterine artery embolization was performed on a 42-year-old woman to treat a postpartum hemorrhage. The woman experienced severe pain immediately following the procedure, and it had persisted for one year when she was referred for chronic unrelenting pain. She was found to have extensive allodynia, myofascial dysfunction, and reduced pain thresholds. A hysterectomy was undertaken. As the pain persisted, botulinum toxin was administered to the lower abdomen in the region of reduced pain thresholds. Partial resolution of pain, physical limitation, and allodynia resolved one year after the hysterectomy and shortly after the injections of four tender regions of the anterior cutaneous nerves with 2.5 and 5.0 IU of botulinum toxin.

CONCLUSIONS

Testing for allodynia is a validated bedside test for pain sensitization. A clinical trial of botulinum toxin is indicated for the management of chronic pelvic pain associated with allodynia and pain sensitization.