The vulvalgesiometer as a device to measure genital pressure-pain threshold

Abstract

The construction and application of the vulvalgesiometer are described. This manually-applied device allows for the quantifiable measurement of pressure-pain thresholds in the external female genital region. A set of five vulvalgesiometers exerting pressures from 3 to 950 g was used in two studies. The goal of the first study was to examine the ability of the vulvalgesiometers to discriminate between women with and without provoked vestibulodynia (PVD). In a matched sample of affected and non-affected women, women with PVD exhibited significantly lower vestibular pressure-pain thresholds as compared to control women. As well, approximately half the sample of women with PVD described the sensation elicited at pressure-pain threshold as similar to the pain experienced during sexual intercourse. The goal of the second study was to investigate the inter-rater reliability of the vulvalgesiometers. In this separate sample of women with and without PVD, each participant was tested for pressure-pain threshold by two different investigators at different times. Results demonstrated high levels of inter-rater reliability, indicating that the vulvalgesiometers can be consistently used by different investigators. Further, results indicated significant negative correlations between pressure-pain thresholds and pain intensity ratings recorded during the cotton-swab test, suggesting that the lower the threshold, the higher the pain ratings during vestibular palpation. The vulvalgesiometers can be utilized for several purposes, including treatment outcome studies and measuring the degree of PVD severity.