Vulvodynia is a chronic pain condition affecting the tissues of the external genitalia in women. Localized provoked vulvodynia (LPV) is a specific subset of vulvodynia in which pain occurs upon touching specific sites on the vestibule (or, less commonly, another defined area), and which has been present for more than three months without a known cause. LPV is characterized both by allodynia (pain in response to a normally non-painful stimulus) and hyperalgesia (excessive pain response), leading to pain with sex, tampon use, and even with activities of daily life, such as sitting or wearing tight clothing.
It is becoming accepted that LPV occurs as a type of hypersensitivity to Candida and other antigens which occurs in susceptible women. LPV is an inflammatory condition with increased levels of B-cells, T-cells, and macrophages in tender areas vs. non-tender areas. The inflammatory process sparks neuroproliferation - growth of new nerve endings - which increases the density of nerve fibers in tender spots, especially in areas of lymphoid aggregates.
The vulvar and vaginal microbiomes are connected to each other; species found in one are often found in the other. In fact, Jayaram et al. showed that all vaginal species were also found on the vestibule, and the dominant vaginal species is also the dominant vestibular species, suggesting that vaginal secretions are a major contributor to the vestibular/vulvar microbiome. Three recent studies have examined the link between vulvodynia and the vaginal microbiome. Results vary by study, with one showing differences in the present vaginal microbiomes between women with vulvodynia and healthy women, and others not showing differences. These may be explainable by inclusion/exclusion criteria (two studies excluded women with active yeast infection; one study specified studying generalized, not localized, vulvodynia; while the others did not specify). But it is agreed that past alterations in the microbiome primed women for excessive pain in response to gentle stimuli.
Vaginal microbiome composition is known to affect immune activation in the vagina and vulva. Campisciano and colleagues showed that vaginal dysbiosis is associated with elevated levels of interleukin (IL)-1ra and IL-2, and lower levels of fibroblast growth factor (FGF)-beta and granulocyte-macrophage colony stimulating factor (GM-CSF) than observed in healthy vaginas. Another study by the same group reported associations between vaginal microbiome composition and IL-1alpha and IL-18. Doerflinger showed activation of the innate immune response by Lactobacillus iners (intermediate flora) and Fannyhessea vaginae (associated with bacterial vaginosis), but not L. crispatus (healthy flora). Of greatest relevance, Falsetta and colleagues investigated expression and activation of the toll-like receptor family and found seven of them to be expressed at higher levels in tissue biospies from tender spots in LPV than in control tissue, and that exposure to HIV increased expression of TLR7 expression and the downstream inflammatory molecule IL-6. Notably, no studies have examined whether improving the vaginal microbiome might lead to reductions in immune signaling in vulvodynia.
Taken together, it is reasonable to hypothesize that the constitution of the vaginal microbiome may influence the hypersensitivity to allergens that comprises the cause of LPV. It is also possible that improving the vaginal microbiome may reduce immune cell recruitment and activation, reducing pain. It is predicted that using sequencing-based technology, differences between the vaginal microbiomes of women with LPV and those without will be detectable. Furthermore, its is predicted that using an over-the-counter feminine hygiene system designed to support a healthy vulvovaginal microbiome will reduce pain in women with LPV over and above any reductions observed with standard-of-care treatment.
The investigators recently conducted an 11-week pilot study of similar design. Women with recurrent bacterial vaginosis (BV) were recruited to use the Flourish Vaginal Care System® for 11 weeks. Primary outcomes were vaginal fluid pH and whether or not women had BV recurrence. By the end of the study, the average vaginal fluid pH had fallen from mean (SD) of 4.54 (0.53) at week 0 to 4.08 (0.40) at week 11. At baseline, 30% of women had active BV. (These women were treated with standard of care oral metronidazole). The number of BV-positive women steadily declined until 5 weeks, at which point no woman had BV. There was no recurrence of BV in any woman through the end of the study. Women reported fewer vulvovaginal symptoms throughout the study. An ad hoc follow-up phone survey a year later showed that only one participant had a recurrence of BV since the end of the study. This study shows that the system we propose to use in the present study is able to effect positive changes in the vaginal microbiome.
A follow-up trial at the same center examining the vaginal microbiome using the same system for 6 months has shown very low recurrence rates, based on preliminary analysis, less than 20% in 6 months, compared with other studies showing 3-month recurrence rates of 43% or 62%. This study, which has completed data collection but has not yet been published, also showed that the vaginal microbiome was in a healthy or intermediate community state type (CST; not BV) during use of the system, though it took over 5 weeks of usage for one woman to move from a BV-like CST to a healthy CST. A similar study is underway using the "Flourish HEC" system - a nearly identical kit with a different vaginal moisturizing gel, gentler for those with sensitivities. To date, five participants are enrolled, and only the initial microbiome tests are available. However, study subjects are reporting that they are feeling good while using the system. It is this Flourish HEC system that will be tested in the present study. We emphasize that the vaginal care system is not intended to modify the body; it has no active drug components. Instead, it is a hygiene system that mimics the proper vaginal environment for a healthy microbiome to develop and thrive.
The investigators hypothesize that regular use of the Flourish HEC Vaginal Care System by women with LPV for three months will colonize the vagina and vulva with healthy bacteria, and that this will reduce inflammation, immune system activation, and neuroproliferation, ultimately reducing pain.
