The diagnostic and therapeutic approach to a patient with chronic pain is different than that for a patient with acute symptoms. Although rarely life threatening, chronic pelvic pain is potentially debilitating and can be a source of frustration for both patient and physician. A multidisciplinaryor integrated approach is most appropriate.
EPIDEMIOLOGY AND PATHOPHYSIOLOGY
The prevalence of chronic pelvic pain is uncertain because of difficulties in obtaining such information, but an estimated 40% of women seeking primary care and 15% of all reproductive-age women have complaints of chronic pelvic pain. More than 50% of women with pelvic pain report not knowing the etiology of theirpain. Pelvic pain is a frequent indication for gynecologic surgery, accounting for 12% of hysterectomies and up to 40% of laparoscopies. Thus this diagnosis may have a significant social and economic impact.
The pathophysiology of chronic pain is not completely understood, and several theories have been proposed. In the traditional somatic model of pain perception, tissue damage at the peripherycauses stimulation of pain receptors, resulting in the perception of pain. This model explains acute pain well but is not appropriate for chronic pain. The biopsychosocial model postulates that a complex interaction of somatic symptoms with various psychosocial factors creates an outcome such as chronic pain. Potential contributing factors include:
patient's response to pain,
psychologic diagnosesand mood states,
family patterns of pain response, and
personal history of physical or sexual abuse.
Recent research has implicated a neurologic explanation for chronic pain. An afferent stimulus, such as pain, may cause permanent alterations to neurologic pathways at the level of the spinal cord, leading to altered responses to future stimuli that result in hyperalgesia,decreased pain threshold, or altered muscle response. Clinically these changes may be associated with chronic pain, recurrence of pain at previous sites of injury, resistance to therapy, or muscle spasm.
A complete history is essential for the proper evaluation of chronic pelvic pain. Initial questions should concern the basic qualities of the pain, includinglocation, character, duration, frequency, patterns of radiation, and alleviating or aggravating factors. The physician notes the chronology of pain with changes over time and any relationship to menstrual cycle, sexual activity, bladder or bowel function, and emotional state. An extensive medical, gynecologic, obstetric, surgical, social, and family history includes previous diagnoses such as pelvicinflammatory disease (PID). The pain's effect on the patient's lifestyle and personal interactions should be determined; a pain or symptom diary may be helpful.
Box 37-1 lists the differential diagnoses of chronic pelvic pain using the classic gynecologic approach of dividing the pain into cyclic and noncyclic categories. The two lists are not mutually exclusive because conditions that generallyproduce cyclic pain may present with noncyclic pain, and vice versa. If the pain is cyclic, the physician obtains a detailed menstrual history, including age at menarche, quantification of amount of bleeding and interval, and regularity and number of days of bleeding. The physician should determine if the pain has been present since menarche or is a
|Box 37-1. Differential Diagnosis of Chronic...