Comparing Vestibule Examination Techniques: Light Touch, Serial Forces, and the Lidocaine Test

J Low Genit Tract Dis. 2021 Jul 1;25(3):236-242. doi: 10.1097/LGT.0000000000000605.

Abstract

Objective: The purpose of this study was to compare techniques and pain scales that assess tenderness in the vulvar vestibule in provoked vestibulodynia, using the cotton swab test and a vulvalgesiometer, and assess topical lidocaine solution with each.

Materials and methods: This randomized study at a specialty vulvar clinic evaluated tender vestibules of reproductive-aged women with vestibulodynia using light rolling cotton swab touch at 6 sites and evaluated the vulvalgesiometer at 2 sites, randomizing the order of the initial tool. Participants reported pain using the Numerical Rating Scale 0-10 and the Verbal Pain Scale 0-3. With the vulvalgesiometer, the pain tolerance threshold was measured using forces of 10, 25, 50, 100, 200, and 300 g. After both initial tests, lidocaine 4% topical solution was applied for 3 minutes, and the swab test and vulvalgesiometer were repeated in the order initially performed, constituting the lidocaine test. Data analysis used t tests, Fisher exact tests, Wilcoxon signed rank tests, and Spearman rank correlation.

Results: Sixteen patients completed the study, 8 starting with each instrument. Light swab touch evoked significant pain, and lidocaine reduced pain to zero or mild levels. The pain threshold was 25 g, and only 38% could tolerate testing past 100 g without lidocaine. The Verbal Pain Scale correlated well with the Numerical Rating Scale.

Conclusions: Light rolling cotton swab touch using the 4-item verbal scale can map vestibulodynia tenderness that can be extinguished by lidocaine, consistent with distinguishing a mucosal condition. Forces by vulvalgesiometer of greater than 100-200 g may evoke pain other than mucosal allodynia.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Anesthetics, Local / pharmacology*
  • Female
  • Humans
  • Lidocaine / pharmacology*
  • Oregon
  • Pain / drug therapy*
  • Pain / psychology
  • Pain Measurement
  • Touch / drug effects
  • Vulva / drug effects*
  • Vulvodynia / drug therapy*
  • Vulvodynia / psychology
  • Young Adult

Substances

  • Anesthetics, Local
  • Lidocaine