Continuing Education Activity

Chronic pelvic pain can be a disabling, chronic, persistent pain, within the pelvis in women. Relatively common, chronic pelvic pain is associated with comorbidities such as irritable bowel syndrome, major depressive disorder, or pelvic inflammatory syndrome. One in seven women in the United States is affected. Chronic pelvic pain is considered a form of chronic regional pain syndrome. The diagnosis of chronic pelvic pain is made after three to six months of pelvic pain and is often based on history or physical; there are numerous associated symptoms or precipitating factors that help establish the diagnosis. While imaging and laboratory findings are often inconclusive in making the diagnosis of chronic pelvic pain, often, they are useful in the diagnosis of a comorbid condition responsible for the development of chronic pelvic pain. An estimated fifty percent of cases remain undiagnosed. This activity reviews the evaluation and treatment of chronic pelvic pain and explains the role of the interprofessional team in managing patients with this condition.

Objectives:

• Identify the etiology of chronic pelvic pain.

• Review the appropriate evaluation of chronic pelvic pain.

• Outline the treatment and management options available for chronic pelvic pain.

• Summarize interprofessional team strategies for improving care coordination and communication to enhance the care of chronic pelvic pain and improve outcomes.

Introduction

Chronic pelvic pain can be a disabling, chronic, persistent pain, within the pelvis in women. Relatively common, chronic pelvic pain is associated with comorbidities such as irritable bowel syndrome, major depressive disorder, or pelvic inflammatory syndrome. One in seven women in the United States is affected. The prevalence is similar to migraine headaches, asthma, and chronic back pain. Chronic pelvic pain is considered a form of chronic regional pain syndrome. The diagnosis of chronic pelvic pain is made after three to six months of pelvic pain and is often based on history or physical; there are numerous associated symptoms or precipitating factors that help establish the diagnosis. While imaging and laboratory findings are often inconclusive in making the diagnosis of chronic pelvic pain, often, they are useful in the diagnosis of a comorbid condition responsible for the development of chronic pelvic pain. An estimated fifty percent of cases remain undiagnosed.

Chronic pelvic pain is a form of centralized pain, where the body develops a low threshold for pain, often a result of chronic pain. For example, if a woman developed endometriosis, the acute pain associated with this condition could become centralized during a three to six months duration, as the pain becomes chronic. In centralized pain, the previous mild to moderate pain is experienced as severe pain (hyperalgesia), or tactile sensations can be interpreted as painful (allodynia). Furthermore, chronic pelvic pain has a strong association with previous physical or emotional trauma. Thus the etiology of chronic pelvic pain may also be related to a functional somatic pain syndrome. Treatment of chronic pelvic pain is often complicated, with limited evidence-based options. Treatment is usually focused on the suspected etiology of the chronic pelvic pain, such as treating a comorbid mood disorder, neuropathy, or uterine dysfunction. Chronic pelvic pain is seen in an estimated four to sixteen percent of women.[1][2][3] Given its prevalence, there must be a high suspicion in patients experiencing chronic pelvic pain. Management of chronic pelvic pain requires an interprofessional team approach; a collaboration between multiple specialties is needed to provide adequate pain relief. Some patients with chronic pelvic pain may benefit from cognitive behavioral therapy and hormone replacement. In contrast, others may require more invasive treatment interventions such as spinal cord stimulation or total hysterectomy.

Etiology

Chronic pelvic pain is associated with dysfunctions such as irritable bowel syndrome, interstitial cystitis, as well as other nonspecific chronic fatigue syndromes. Chronic pelvic pain is also associated with mental health disorders, including posttraumatic stress disorder and major depressive disorder. The relationship between chronic pelvic pain and comorbid conditions is often the primary focus of its diagnosis and management. In over half of cases of chronic pelvic pain, there is comorbid endometriosis, pelvic adhesions, irritable bowel, or interstitial cystitis.[4][5] Furthermore, multiple comorbidities can be present simultaneously alongside chronic pelvic pain.[4][6] Chronic pelvic pain is a form of reflex dystrophy, where there is both a neurological component to symptoms, as well as a psychological component.[7][8] The pathophysiology of chronic pelvic pain is likely that of centralized pain. Patients with chronic pelvic pain develop hyperesthesia and allodynia as a result of pelvic floor dysfunction.[7][8] Many comorbidities can lead to chronic pain; chronic cystitis, endometriosis, adhesions, or musculoskeletal injury are but a few associated with chronic pelvic pain.[9] Many women have pain symptoms for over two years before seeking medical care.[10] The persistent nature of the pain is what puts the patient at risk for centralization and the development of chronic pelvic pain. As chronic pain develops, the central nervous system undergoes a systemic change and becomes persistently in a state of high activity. When this occurs, the central nervous system responds to various stimuli as if they were painful. Chronic pelvic pain's etiology is likely secondary to comorbidities that caused chronic pain.[11] There is a synergistic effect of pain that can develop. As one organ system becomes dysfunctional, as in the case of interstitial cystitis, another organ can also develop pathology, such as in irritable bowel syndrome. As comorbidities develop, the chronic nature of symptoms leads to centralized pain, only enhancing the pain more. Collectively, persistent and increased sensitivity to pain becomes chronic pelvic pain.[12][13]

Pain can either be widespread as in chronic pain syndrome or more focal, as seen in chronic pelvic pain. Location often aids in diagnosis and management. Patients with widespread symptoms of pain, including pelvic pain, pain of multiple limbs, axial skeleton, and pain above the diaphragm, have much more significant psychological comorbidities (generalized anxiety disorder, major depressive disorder, and posttraumatic stress disorder) compared to focal symptoms. Emotional state and stress levels influence visceral pain, such as chronic pelvic pain.[14][15] Patients with widespread symptoms require a longer duration of treatments compared to patients with more focal pelvic pain.[16][17] There is a sizeable psychiatric component of chronic pelvic pain. It is theorized that chronic pelvic pain has both environmental and genetic elements. Women with chronic pelvic pain have a higher incidence of depression, anxiety, and sleep disorders. However, repetitive trauma, such as childhood sexual abuse, could explain both the somatic symptoms of chronic pelvic pain, as well as the associated posttraumatic stress.[18][19][20][21] Anatomical changes from various pathology may also be the primary source in the development of chronic pelvic pain. Leiomyomas, nerve root entrapment, sacral cysts, and cauda equina syndrome have all been associated with chronic pelvic pain.[22][23] Patients with pelvic inflammatory disease are more likely to develop chronic pelvic pain. Furthermore, the risk of developing chronic pelvic pain is increased if the patient is also a smoker, is in poor mental health, and had two or more episodes of pelvic inflammatory disease.[5] In many cases of chronic pelvic pain, comorbid irritable bowel syndrome was neither previously diagnosed nor treated before the diagnosis.[24] Endometriosis is a comorbidity associated with both chronic pelvic pain and irritable bowel syndrome.[22][25][26]

Epidemiology

Thirty-five percent of patients with chronic pelvic pain have comorbid irritable bowel syndrome.[5] An estimated sixty-one percent of women with bladder pain syndrome have comorbid chronic pelvic pain, while almost fifty percent of women with endometriosis suffer from chronic pelvic pain.[6] The prevalence of chronic pelvic pain is approximately between four to sixteen percent of women. Only a third of women suffering from chronic pelvic pain seek medical care.[2][22][27] Gynecological comorbidities are seen in an estimated twenty percent of patients with chronic pain. While urological and gastrointestinal comorbidities are more prevalent, endometriosis is by far the most common comorbidity associated with patients seeking medical care with chronic pelvic pain.[10] Of the patients with chronic pelvic pain who undergo elective surgery, twenty to eighty percent of patients are diagnosed with endometriosis.

In comparison, seventy percent of patients with a previous diagnosis of endometriosis are diagnosed with chronic pelvic pain.[28][29] Ninety-nine percent of all cases of chronic pelvic pain are in females.[27] Patients with a past medical history significant for pelvic trauma or surgery are at a much higher risk of developing chronic pelvic pain compared to the general population. Twenty-eight percent of women develop persistent pelvic pain following an elective cesarean delivery, three months postoperatively, while twenty percent of women continue to have persistent pain six months postoperatively.[30] Almost half of women with chronic pelvic pain report a previous history of sexual or physical abuse.

Furthermore, of patients with both a prior history of abuse and chronic pelvic pain, one-third of these patients also had comorbid posttraumatic stress disorder.[31][32] Up to thirty percent of women with a previous history of pelvic inflammatory disease develop chronic pelvic pain. Of patients who undergo elective hysterectomy due to chronic pelvic pain secondary to adenomyosis, twenty-five percent of these patients continue to experience postoperative pain.[33][34]

Pathophysiology

The pathophysiology depends on the cause of the pain. For example, in endometriosis, the pain is cyclical due to recurrent bleeding in the endometriotic implants. In pelvic congestion syndrome, the pain is due to engorged and dilated pelvic veins causing the decreased venous washout.

History and Physical

When obtaining a history from a patient with suspected chronic pelvic pain, there is often comorbid chronic pain — furthermore, possible signs and symptoms of allodynia or hyperalgesia, suggestive of central sensitization. The etiology of chronic pelvic pain can usually be determined by a full past medical and surgical history, as well as the patient's gynecological and labor history.

Chronic pelvic pain in women is often defined as persistent, noncyclic pain, but can also be cyclical. The patient's pain is located within the pelvis and has lasted greater than six months duration. The pain must also be unrelated to pregnancy.[11] The consistency can be constant or episodic. Some definitions do not consider cyclical pain to be a part of chronic pelvic pain, given this could be defined as dysmenorrhea.[35][36]

The patient's history should include questions about precipitating and alleviating factors, including the association between menses and pain, urination, sexual activity, and bowel movements, and response to prior treatments. Pain may identify other areas where the patient experiences pain or may reveal a dermatomal distribution, suggesting a non-visceral source. Furthermore, the evaluation of mental health disorders should be completed, as well. Associated symptoms for patients with chronic pelvic pain include but are not limited to, gastrointestinal, urinary, sexual, and psychological, and menstrual symptoms. Also, impaired quality of life should be assessed. Patients with chronic pelvic pain can often experience motor or autonomic dysfunction.[37] On history, cramping pain, hot, burning, or electrical type pain should be differentiated from sharp or dull pain. Pain fluctuation with the menstrual cycle compared to the constant pain should be distinguished. Pain with urination or defecation, postcoital bleeding, postmenopausal bleeding, the postmenopausal onset of pain, history of prior abdominal surgery or previous abdominal infection, or unexplained weight loss should also be summarized as part of the history. 

Red flag findings that may indicate systemic disease include postcoital bleeding, postmenopausal bleeding or onset of pain, unexplained weight loss, pelvic mass, and hematuria. Physical examination, including a gynecological speculum and bimanual examination, and a full abdominal exam, should be completed. The external genitalia should be examined and an examination of the pelvic floor musculature for tenderness or hypertonicity should be done as well. On physical exam, evaluation for an adnexal mass, enlarged or tender uterus, lack of uterine mobility on bimanual exam should be completed. Pain upon palpation of the lumbar spine, sacroiliac joint, and pelvis should be noted.[11] The Carnett test should also be done to determine if there is abdominal wall pain for patients experiencing pelvic pain.

For the Carnett test, the patient is asked to raise both of their legs off the exam table while in a supine position. The provider places their finger on the patient's painful abdominal area to determine whether the patient's pain increases with the legs are flexed, and the abdominal muscles have contracted. In myofascial pain, the patient is likely to experience more considerable pain with leg flexion, while visceral pain improves with leg flexion. Women with chronic pelvic pain have also been found to have up to five times more asymmetry of their iliac crest height and symphyseal levels.[38]

Evaluation

Diagnosis is based on findings from the history and physical examination. If the findings on history and physical are suggestive of a specific diagnosis that is causing chronic pelvic pain, the diagnosis should be confirmed. 

A cotton swab can be applied to the abdominal to help determine if there is a cutaneous source of pain. Completing the cotton tip applicator test helps determine if there is cutaneous allodynia. This test is 100% specific for patients with chronic pelvic pain.[39]

The effects on quality of life and function should also be part of the assessment and can be completed by filling out a standardized questionnaire.[40]

The first step in the evaluation of a patient with suspected chronic pelvic pain is to determine if they have any alarm symptoms, concern for acute abdomen, or potential malignancy. If there are no alarm symptoms and no accurate diagnosis, then labs and imaging are warranted. The initial workup would include a complete blood count (CBC), erythrocyte sedimentation rate (ESR), urinalysis (UA), a urine pregnancy test, testing for gonorrhea and chlamydia, and a pelvic ultrasound. If a specific etiology is suggested after the initial workup, it should be evaluated and treated. Pelvic ultrasonography is indicated to rule out anatomic abnormalities. Ordering transvaginal ultrasonography is an essential part of the initial workup for suspected chronic pelvic pain. It can help identify cysts, masses, and adenomyosis. Furthermore, ultrasound detects hydrosalpinx, an indicator of pelvic inflammatory disease, a comorbidity often seen in chronic pelvic pain. Separately, a pelvic ultrasound is useful to identify masses less than four centimeters that may be missed on the physical exam.[41][42] Magnetic resonance imaging (MRI) may be needed following an ultrasound if abnormalities are seen.[43] 

Separately, if the patient is experiencing severe, uncontrolled pain, or there is a concern for acute abdomen, the patient should be referred for laparoscopic surgery or sent to the emergency department.[44][45] If laparoscopic surgery is inconclusive, the patient's chronic pelvic pain is likely secondary to chronic regional pain syndrome.

Diagnostic nerve blocks can be useful to determine if the patient with chronic pelvic pain complains of symptoms of neuropathic pain. If a sacral nerve root is numbed from a nerve block, and the patient's pain is eliminated, this helps confirm the diagnosis of chronic pelvic pain secondary to peripheral nerve dysfunction.[46] 

Pain mapping can also be done during laparoscopic surgery, and the patient is under local sedation. The patient's tissue is probed with surgical tools. The patient is asked about the severity of their pain. It can be a helpful test to focus treatment on the specific area of pain.[47]

Treatment / Management

The evidence-based literature for the treatment of chronic pelvic pain is limited. For nonspecific chronic pelvic pain, the focus of treatment is often directed at symptomatic pain relief.[48] The approach to treating chronic pelvic illnesses should both be focused on the underlying pathology, as well as the psychological aspect of pain, including treatment of a comorbid mood disorder. For cases of chronic pelvic pain where the origin of the pain is known, the focus of treatment is to treat the underlying disease process. However, if the source of the pain is unknown, it is recommended for the patient to undergo further evaluation to find the underlying disease process.

The first step in the treatment of a patient with chronic pelvic pain with an unknown source of their pain is over-the-counter analgesics (acetaminophen, nonsteroidal anti-inflammatory drugs). These pain relievers are typically well-tolerated. If there is adequate pain relief, no further pain management is needed at this time. If there is inadequate pain relief and a cyclical component to the patient's pelvic pain, hormonal replacement therapy is recommended (either oral contraceptive pills, depot medroxyprogesterone, or an intrauterine device). If hormonal treatment is ineffective, or the patient's pain was not cyclical, or their pelvic pain is suspected to be neuropathic, it is essential to evaluate the patient for an underlying mood disorder. If a mood disorder is presumed, antidepressant therapy (selective serotonin reuptake inhibitors) is recommended. If a patient with suspected chronic pelvic pain secondary to neuropathic pain does not have an underlying mood disorder, various treatment options exist. Depending on the patient's preference and their various comorbidities, the patient may benefit from tricyclic antidepressants (TCAs), pregabalin, gabapentin, or serotonin-norepinephrine reuptake inhibitors (SNRIs) such as venlafaxine, or duloxetine. If pain is uncontrolled with these various treatment options, it is recommended to refer to a pain medicine specialist and consider a trial of opioid analgesics.[45][49][50] For cases of suspected chronic pelvic pain secondary to suspected neuropathy, gabapentin used as a single agent or in combination with amitriptyline, has been shown to be more effective than amitriptyline used alone.[48][49][51]

Adjunct, non-pharmacological treatment should also be offered. Pelvic floor physical therapy may be beneficial in chronic pelvic pain. Its effectiveness aids in the diagnosis of a musculoskeletal origin of chronic pelvic pain.[38][52] Cognitive-behavioral therapy also plays an integral part in treatment. It has been shown to decrease pain, stress, and improve function.[53] Mindfulness can be taught as a component of both physical therapy and cognitive behavioral therapy.[54] In severe cases, peripheral nerve blocks and neuromodulation of sacral nerves may also be necessary. For chronic pelvic pain secondary to the uterine origin, a hysterectomy can be considered, but it is often the last option. Oral contraceptive pills are unlikely to be beneficial in patients without cyclical pelvic pain.[55] Cyclobenzaprine is an effective pain reliever in patients with chronic pelvic pain, as well as has been shown to improve sleep.[56][57] If there is suspected sacral nerve injury, a local corticosteroid injection can be both diagnostic to determine peripheral nerve involvement in chronic pelvic pain, and therapeutic, providing pain relief. Some providers attempt to try pharmacological therapy alongside various interventional procedures.

If a local steroid injection is successful, either radiofrequency ablation, peripheral nerve blocks, or neuromodulation with a spinal cord stimulator may be a viable treatment option.[58][59] Botulinum toxin injections for patients with chronic pelvic pain have been shown to decrease pain with sexual activity, decrease pelvic pressure, as well as persistent, non-cyclical pelvic pain.[60] Cutaneous treatment option such as trigger point injections with a local anesthetic such as lidocaine is another consideration for short term pain relief. Interestingly, patient pain relief lasts longer than the duration of the injection's effectiveness. These injections are often done to relieve hypertonicity and pain secondary to the pelvic floor or abdominal wall muscles. If trigger point injections are beneficial, they are not only therapeutic but potentially diagnostic for myofascial pain syndrome. Myofascial pain has been associated with centralized pain.[37][61][62] Alongside cognitive behavioral therapy, patient education regarding their chronic pelvic pain, including the psychological aspect of their pain, is beneficial.[63][64]

Differential Diagnosis

There are multiple etiologies of chronic pelvic pain that are part of the differential diagnosis. As the patient’s pain becomes chronic, it centralizes, leading to chronic pelvic pain. A list of the various possible etiologies for chronic pelvic pain are listed below:

• Gynecological - Endometriosis, pelvic inflammatory disease, pelvic adhesion disease, recurrent ovarian cysts, leiomyoma, adenomyosis, hydrosalpinx, and post-tubal ligation pain syndrome
• Gastroenterological - Irritable bowel syndrome, celiac disease, inflammatory bowel disease, colorectal carcinoma, and hernias
• Urological - Interstitial cystitis (painful bladder syndrome), recurrent cystitis
• Radiation cystitis, chronic urolithiasis, bladder cancer, and urethral syndrome
• Musculoskeletal - Abdominal wall myofascial pain, fibromyalgia, coccygodynia, pelvic floor tension myalgia, piriformis syndrome
• Neurological/vascular - Ilioinguinal nerve entrapment, iliohypogastric nerve entrapment, pudendal neuralgia, spinal cord injury, pelvic congestion syndrome, peripheral neuropathy, and vulvar varicosities

The five most common etiologies of chronic pelvic pain include irritable bowel syndrome, musculoskeletal pelvic floor pain, painful bladder syndrome, peripheral neuropathy, and chronic uterine pain disorders.

Prognosis

Following any gynecological surgical procedure related to chronic pelvic pain, there is a forty-six percent improvement of the patients' pain, and a thirty-one percent improvement of symptoms of comorbid depression.[9] Prognosis is often poor in patients with chronic pelvic pain, similar to other chronic pain syndromes. Treating the underlying origin of the patient's pain leads to the best improvements in quality of life, as well as treating comorbid mood disorders. 

Physical therapy can be a useful treatment modality in chronic pelvic pain — specifically, pelvic floor therapy. After completing therapy, patients with chronic pelvic pain used 22% less pharmacological pain relievers compared to patients who did not participate in treatment.[65] Furthermore, patients have been shown to have decreased pain as well as decreased urinary frequency and urgency in patients with chronic pelvic pain secondary to painful bladder syndrome.[66]  

Hysterectomy led to fifty percent pain relief, in forty percent of patients with chronic pelvic pain, secondary to a gynecological origin.[67] Yet, in up to forty percent of patients, chronic pelvic pain will continue, and five percent of patients will complain of worsening pain following surgery.[68]

The prognosis of patients with chronic pelvic pain was better in patients with fewer comorbidities.[69]

It is unclear when the optimal time for patients with chronic pelvic pain to opt for surgery. 

Also, complicating matters is the lack of long-term research studies in the treatment of chronic pelvic pain.

Many of the endpoints of studies are measured in months rather than years.[70][71] 

Pain mapping is useful to reduce pain in about fifty percent of patients.[47]

Complications

It is essential when discussing chronic pelvic pain to be mindful of the history of trauma. Many women with a history of chronic pelvic pain have a history of abuse and suffer from comorbid posttraumatic stress disorder.[32] 

Patients with gynecological etiologies of their chronic pelvic pain, who elect to undergo an elective hysterectomy may continue to experience pelvic pain postoperatively. 

Tolerance to opioid analgesics can develop over time requiring increased dosages for adequate pain relief of their chronic pelvic pain. 

Insomnia is prevalent in patients with centralized pain disorders and should be treated appropriately.[72] 

Specifically, in chronic pelvic pain, laparoscopic surgery is inconclusive in forty percent of cases in helping identify a source of the patient's pain.[73] Infection and bleeding are but a few complications associated with laparoscopic surgery and or hysterectomy.

Deterrence and Patient Education

Patients with chronic pelvic pain should be thoroughly educated regarding the multifactorial state of their condition. They should be encouraged to maximize their state of health by getting regular exercise, adequate sleep, and eating a well-balanced diet. They should also be made aware of the importance of open communication with their specialists and adherence to all prescribed medications and other treatment modalities.

Enhancing Healthcare Team Outcomes

Managing chronic pelvic requires an interprofessional team of healthcare professionals that includes a physical therapist, psychologist, pharmacist, and several clinicians in different specialties. Without proper management, the morbidity from chronic pelvic pain is high. There should be a high clinical suspicion for chronic pelvic pain in patients with a history of chronic pain or various chronic diseases.

Treatment of the primary source of pain and diagnosis of chronic pelvic pain often falls upon the primary clinician. Treatment of comorbid conditions such as irritable bowel syndrome or major depressive disorder is critical in the treatment of chronic pain. Referral to a gynecological surgeon may be required in the case of diagnostic exploratory laparotomy or elective laparoscopic hysterectomy. In some cases of chronic pelvic pain, where the bladder is the likely etiology of chronic pelvic pain, a urologist can be consulted for further evaluation. A pain medicine specialist can perform various trigger point injections into the pelvic floor muscles, nerve blocks, radiofrequency ablation technique, installation of a spinal cord stimulator, facilitate biofeedback therapy, and relaxation exercises. Depending on the severity of the patient's pain, prescription pain relievers may be necessary for adequate analgesia. A pharmacist helps coordinate care and helps aid in patient understanding of their medications, including proper usage and side effects. A physical therapist is a valuable member of the team. The therapist often aids in stretching exercises, relaxation techniques, and strengthening pelvic floor muscles. A cognitive-behavioral therapist aids in the coping and understanding of a patient's pain. The therapist may also have experience with biofeedback. Pain management nurses assist in assessing patients and provide education.

The management of chronic pelvic pain can be a lifelong condition requiring continuous treatment. Only by working as an interprofessional team can the morbidity of chronic pelvic pain be reduced. Multiple diagnostic and therapeutic treatment modalities are helpful in the management of chronic pelvic pain. [Level 5]