Decreased mechanical pain threshold in the vestibular mucosa of women using oral contraceptives: a contributing factor in vulvar vestibulitis?

OBJECTIVE: To analyze possible differences in somatosensory perception in the vestibular mucosa in healthy women associated with the use of oral contraceptives.

STUDY DESIGN: Quantitative sensory tests were performed on the vestibular mucosa in 39 healthy women. Twenty women were using oral contraceptives containing 30-40 microg ethinyl estradiol combined with various progestins; 19 women with regular menstrual periods not using oral contraceptives served as controls. The testing included mechanical and heat pain thresholds and detection thresholds of warmth and cold in the anterior and posterior part of the vestibule.

RESULTS: Significant lower mechanical pain thresholds were observed in both areas tested in women using oral contraceptives. The most sensitive area was the posterior vestibule in the group using oral contraceptives with a mechanical pain threshold of 72 +/- 10 ( +/-SEM) mN as compared to 161 +/- 3 mN (p < 0.01), in the controls. The result of the thermotest showed no significant differences between the groups.

CONCLUSION: Oral contraceptives may induce increased sensitivity in the vestibular mucosa in healthy women and might be one contributingfactor in the development of vulvar vestibulitis.