Background
Vulvodynia is a chronic vulvar pain disorder and fibromyalgia is a chronic widespread musculoskeletal pain disorder; both of unknown etiology. Association of these conditions is well documented. Intra-vaginal algometer measurement of tenderness to pressure applied to the pelvic floor muscles helps to define vulvodynia associated with musculoskeletal factors. Women with both vulvodynia and fibromyalgia might have increased pelvic muscle pain compared to women with vulvodynia alone, defining the possible link of these two conditions.
Objective
1) correlate pain intensity during the non-genital tender point tenderness examination to pain intensity with the vaginal algometer in women with provoked vestibulodynia, 2) determine whether subjects with provoked vestibulodynia and fibromyalgia had higher pain intensity scores with the vaginal algometer than those without fibromyalgia.
Study Design
Ninety-two subjects referred for vulvar pain were confirmed to have provoked vestibulodynia using the cotton swab test. A diagnosis of fibromyalgia was made if pain was present (Numerical rating scale> 1) in at least 11 sites of the 18-point non-genital tender point tenderness exam. Vaginal pain sensitivity was measured using an intra-vaginal pressure algometer, where 0.1, 0.3, and 0.5 kg/cm2 forces were applied digitally in random assignment by force and location to the right and left iliococcygeus muscle regions and the posterior vaginal wall. Both tender point tenderness and algometer pain intensity were reported on a 0 (no pain) to 10 (worse pain) numeric rating scale. Correlations were computed between the composite pain intensity (total of rating scale from each pressure threshold at specified site) of non-genital and those of iliococcygeus regions and the posterior vaginal wall. Independent t-tests were used to determine differences in iliococcygeus regions and the posterior vaginal algometer pain ratings and presence or absence of fibromyalgia. The significance level was at P < .05. The data were expressed as mean ± standard deviation.
Results
A significant correlation was found between numerical rating scale pain ratings on the non-genital tender point tenderness exam and algometer testing on the iliococcygeus region (r = 0.44, p <.0001), and the posterior vaginal wall (r = 0.45, p < .0001). Subjects with fibromyalgia by tender point tenderness, had significantly higher iliococcygeal pain (6.14 ± 2.07 vs. 3.74 ± 2.22, p = 0.0001), and posterior vaginal wall pain (5.67 ± 2.10 vs. 3.07 ± 2.16, p < 0.0001) than women without fibromyalgia by tender point tenderness.
Conclusion
Women with provoked vestibulodynia who experience more severe pain with nongenital tender point palpation also experience more deep vaginal pain on pelvic exam. Those who fulfill the diagnosis of fibromyalgia show significantly more intense deep vaginal pain to palpation of iliococcygeus muscles and posterior vaginal wall. Further research using a more precise definition of fibromyalgia is necessary to confirm this relationship, bu...