Multimodal Vulvar and Peripheral Sensitivity Among Women With Vulvodynia: A Case-Control Study.

OBJECTIVE: To assess differences in vulvar and peripheral sensitivity between women with and without vulvodynia.
METHODS: Women with vulvodynia (n = 41) and age-matched controls (n = 43) seen in the outpatient setting were evaluated via surveys, clinical examination, and multimodal sensory testing (pressure, heat, cold, vibration, and electrical stimulation). The relationships between sensitivity to various sensory modalities and case/control status, as well as by vulvodynia subgroups, were assessed using logistic regression.
RESULTS: Women with vulvodynia were more sensitive to pressure and to electrical stimuli than were control women at the vulva (median, 22 vs 230 g and 0.495 vs 0.769 mA, respectively; P < 0.001 for each) and at the thumb (median, 2500 vs 4250 g and 0.578 vs 0.764 mA, respectively; P = 0.006 for pressure, P < 0.001 for electrical stimulation). Heat, cold, and vibration detection thresholds did not differ significantly between these groups (P > 0.025). Those reporting spontaneous pain versus provoked pain had greater pressure sensitivity to the thumb (median, 1850 vs 2690 g; P = 0.020) and greater electrical sensitivity at the introitus (0.450 vs 0.608 mA; P = 0.011), and those with primary versus secondary vulvodynia had substantially greater pressure sensitivity to the thumb (median, 2438 vs 3125 g, P = 0.004). However, having localized versus generalized vulvodynia was not associated with differences in pressure or electrical sensitivity.
CONCLUSIONS: Sensitivities to pressure and electrical stimuli are greater among vulvodynia cases than among controls and support 2 previously defined subgroups-those reporting spontaneous pain versus those whose pain only occurred when provoked, and those with primary versus secondary vulvodynia.