Umbilical hypersensitivity in women with primary vestibulodynia.

Objective: To provide evidence that primary vestibulodynia (PV) is a congenital defect in tissue derived from the primitive urogenital sinus.

Study Design: Twenty-two women with PV, 16 with secondary vestibulodynia (SV) and 8 controls were included in this study. Subjects underwent a complete history and physical examination, including assessment with a vulvalgesiometer to measure the sensory and pain detection thresholds in the vulvar vestibule, deltoid and umbilicus.

Results: The median vestibular sensitivity was 5 g in the PV group and 10 g in the SV group (p= 0.77). The median umbilical pain thresholds for the PV, SV and control groups were 115, 675 and 500 g, respectively. Women with PV displayed a significantly higher level of umbilical sensitivity (a substantially lower pain threshold) compared with women with SV and the control group (p = 0.0001 and 0.002, respectively). There was no difference in umbilical sensitivity between the SV and control groups.

Conclusion: Because both the umbilicus and vulvar vestibule are derived from primitive urogenital sinus, this suggests that women with PV may have a congenital abnormality in urogenital - sinus-derived epithelium.