chronic pelvic pain in women

introduction

a large proportion of women experience pelvic pain, often over years, most define chronic pain as pain lasting more than 6 months and such pains affect 2-20% of women depending upon definition
virtually every normal, physiologic event that occurs within a woman's pelvis is associated with pain which vary in duration, intensity and are associated with events such as ovulation, menstruation, pregnancy, labour and childbirth, thus not all pelvic pain needs surgical or pharmacologic intervention or even investigation.
the patient with acute pelvic pain should be managed as per the patient with acute abdominal pain in the ED
for patients with pelvic pain primarily related to menses - see dysmenorrhoea
however, some women experience more severe recurrent pains which do deserve clinical assessment and investigation, in particular to rule out potentially treatable conditions such as large ovarian cysts and other cysts in the adnexae, pelvic inflammatory disease (PID), and endometriosis, but also less well diagnosed causes such as neuropathic pelvic pain which is becoming increasingly recognised as a significant cause of otherwise idiopathic chronic pelvic pain.
chronic pelvic pain may be associated with:
- exacerbation of dysmenorrhoea
- dysuria
- dyschesia (painful defecation) - this is especially likely in those with endometriosis
- dyspareunia
- depression

endometriosis, ovarian endomtrioma and adenomyosis
pelvic inflammatory disease (PID)
large ovarian cysts and other cysts in the adnexae
uterine fibroids (leiomyomas)
painful bladder syndromes
- interstitial cystitis
vulvovaginitis
pelvic muscle pain
irritable bowel syndrome (IBS)
adhesions
venous causes:
- “pelvic venous congestion” / “ovarian vein reflux”
  - said to be the cause of 13-40% of chronic pelvic pain
  - mainly in younger women who have had at least 2 children, usually unilateral but may be bilateral
  - may have a PH of vulval varicosities during pregnancy
  - pain is worse on standing
  - may require venography to diagnose
  - may respond to medroxyprogesterone acetate or goserelin, otherwise pelvic vein embolism may be tried ¹⁾
- May-Thurmer syndrome (rare cause)
  - left common iliac vein compression by the right common iliac artery
  - usually known for predisposition to deep venous thrombosis (DVT) but may cause pelvic pain which responds to stenting ²⁾
idiopathic chronic pelvic pain syndrome accounts for around 50% of cases
- some may be related to a PH of sexual abuse or psychological morbidity
neuropathic pelvic pain (see below)

generally results from damage to the nervous system including axons of peripheral nerves or deafferentiation of neurons within the CNS (neurons lose their accustomed afferent input).
this can and does cross neuroanatomical boundaries, often presenting viscerally as referred pain (thereby potentialy causing misdiagnosis) and eliciting pain descriptors such as burning, shooting, stabbing, and searing.
this may also be caused by inguinal or pelvic herniae which are commonly occult and difficult to detect clinically in women - abdominal fat and nerves may become entrapped causing neuropathic pain - often radiating to labia majora or anterior thigh if inguinal
eg. pudendal neuralgia
tools to help diagnosis neuropathic pain include:
- questionnaires:
  - painDETECT
  - DN4 (Douleur Neuropathetique en 4)
  - LANSS (Leeds Assessment of Neuropathic Symptoms and Signs)
  - S-LANSS (self-assessed LANSS)
  - NPS (Neuropathic Pain Scale)

MJA vol 190 no 1: Letter to the editor. Vivian and Barnard. p47
Prevalence of chronic pain with neuropathic characteristics in the general population. Pain 2008; 136: 380-387

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