Vulvodynia: an introduction and critical review of a chronic pain condition

Exploring Localized Provoked Vulvodynia: Insights from Animal Model Research

Provoked vulvodynia represents a challenging chronic pain condition, characterized by its multifactorial origins. The inherent complexities of human-based studies have necessitated the use of animal models to enrich our understanding of vulvodynia's pathophysiology. This review aims to provide an exhaustive examination of the various animal models employed in this research domain. A comprehensive search was conducted on PubMed, utilizing keywords such as "vulvodynia", "chronic vulvar pain", "vulvodynia induction", and "animal models of vulvodynia" to identify pertinent studies. The search yielded three primary animal models for vulvodynia: inflammation-induced, allergy-induced, and hormone-induced. Additionally, six agents capable of triggering the condition through diverse pathways were identified, including factors contributing to hyperinnervation, mast cell proliferation, involvement of other immune cells, inflammatory cytokines, and neurotransmitters. This review systematically outlines the various animal models developed to study the pathogenesis of provoked vulvodynia. Understanding these models is crucial for the exploration of preventative measures, the development of novel treatments, and the overall advancement of research within the field.

Trauma, attachment style, and somatization: a study of women with dyspareunia and women survivors of sexual abuse

Background

Evidence points toward shared characteristics between female survivors of sexual abuse and women with dyspareunia. This study explored, for the first time, similarities and differences between women who were exposed to sexual abuse to those with dyspareunia, in order to examine whether insecure attachment styles and high somatization level are associated with trauma among women with dyspareunia.

Methods

Attachment styles were explored using the Experience in Close Relationships Scale to reflect participants’ levels of anxiety and avoidance. Somatization was assessed using the Brief Symptom Inventory focusing on the frequency of painful and non-painful bodily complaints. Trauma was categorized into three levels: sexual trauma, nonsexual trauma, and no trauma.

Results

Sexually abused (SA) women (n = 21) compared to women with dyspareunia (dys) (n = 44) exhibited insecure attachment styles, as expressed by high levels of avoidance (SA 4.10 ± 0.99 vs. dys 3.08 ± 1.04, t₍₆₁₎ = 2.66, p = .01) and anxiety (SA 4.29 ± 1.22 vs. dys 3.49 ± 1.04, t₍₆₁₎ = 3.61, p = .001), and higher somatization (21.00 ± 8.25 vs. 13.07 ± 7.57, t₍₅₉₎ = 3.63, p = .001). Attachment and somatization level did not differ significantly between women with dyspareunia without trauma to those with nonsexual trauma.

Conclusions

Our findings emphasized the unique role of sexual trauma as a contributing factor to the augmentation of perceived bodily symptoms and to insecure attachment style. This illuminates the importance of disclosing previous sexual abuse history among women with dyspareunia.

Vulvodynia attitudes in a sample of Canadian post-graduate medical trainees

Physicians play a critical role in addressing sexual health in medical practice, including pain during intercourse. Vulvodynia is a prevalent cause of pain, however, related training is limited and variable. In addition, physician attitudes toward pain and sexuality may affect behaviour and therefore patient outcomes. This study's objectives were to: 1) determine whether post-graduate trainees hold more positive attitudes toward women presenting with vulvovaginal pain with (versus without) an identifiable cause; and 2) examine attitudinal predictors of comfort treating vulvodynia and attitudes toward patients with this presentation. Residents in Canadian Obstetrics and Gynecology (OBGYN) and Family Medicine (FM) programs participated in an online survey (N=99). Respondents completed questionnaires related to demographics, sexuality-related training, sexual attitudes, and comfort treating and attitudes toward vulvovaginal pain and its symptoms. Residents reported significantly more positive attitudes toward patients with visible pathology versus no identifiable cause for vulvovaginal pain, regardless of medical specialty, p<.001. In OBGYN residents, general comfort discussing sexuality in medical practice significantly predicted comfort treating vulvodynia and its symptoms (p<.001), and attitudes toward women with vulvodynia (p<.05). Demographic, training, and attitudinal variables did not significantly predict vulvodynia outcome measures in FM residents. This study of medical residents identified different attitudes based on vulvovaginal pain presentation, and identified predictors of attitudes and comfort treating vulvodynia in OBGYN residents. Findings suggest pathways by which health care experiences may influence outcomes in this population, and have important implications for resident training.

Clitorodynia: A Descriptive Study of Clitoral Pain

INTRODUCTION

Clitorodynia is classified as a type of localized vulvodynia. Our knowledge of this problem is limited to case studies and one published report.

AIMS

The objective of the present study was to describe quantitatively the clinical characteristics of clitoral pain, to assess interference with sexual function, and to investigate whether clitoral pain is a unitary category.

METHODS

One hundred twenty-six women with clitoral pain completed an online questionnaire that assessed demographic information, descriptive pain characteristics, intensity and impact on daily activities, sexual function, and gynecological and medical histories.

MAIN OUTCOME MEASURES

The main outcome measures used for the study are the following: clitoral pain characteristics (e.g., intensity, duration, quality, distress, etc.), short-form McGill pain questionnaire-2, and the female sexual function index.

RESULTS

Clitoral pain is characterized by frequent and intense pain episodes that can either be provoked or unprovoked, and causes significant impairment in both daily and sexual function. The pain can be localized to the clitoris only or can occur with other genital pain. Comorbidity with other chronic pain disorders is common. A cluster analysis suggested two distinct patterns of clitoral pain, one localized and one generalized.

CONCLUSION

Our findings indicate that women with clitoral pain suffer from significant, distressing, and often long-term pain, which interferes with sexual and daily activities. Two subtypes of clitoral pain may exist, each with distinct pain characteristics and subjective experiences.

Persistent genital hyperinnervation following progesterone administration to adolescent female rats

Provoked vestibulodynia, a female pelvic pain syndrome affecting substantial numbers of women, is characterized by genital hypersensitivity and sensory hyperinnervation. Previous studies have shown that the risk of developing provoked vestibulodynia is markedly elevated following adolescent use of oral contraceptives with high progesterone content. We hypothesized that progesterone, a steroid hormone with known neurotropic properties, may alter genital innervation through direct or indirect actions. Female Sprague Dawley rats received progesterone (20 mg/kg subcutaneously) from Days 20-27; tissue was removed for analysis in some rats on Day 28, while others were ovariectomized on Day 43 and infused for 7 days with vehicle or 17beta estradiol. Progesterone resulted in overall increases in vaginal innervation at both Day 28 and 50 due to proliferation of peptidergic sensory and sympathetic (but not parasympathetic) axons. Estradiol reduced innervation in progesterone-treated and untreated groups. To assess the mechanisms of sensory hyperinnervation, we cultured dissociated dorsal root ganglion neurons and found that progesterone increases neurite outgrowth by small unmyelinated (but not myelinated) sensory neurons, it was receptor mediated, and it was nonadditive with NGF. Pretreatment of ganglion with progesterone also increased neurite outgrowth in response to vaginal target explants. However, pretreatment of vaginal target with progesterone did not improve outgrowth. We conclude that adolescent progesterone exposure may contribute to provoked vestibulodynia by eliciting persistent genital hyperinnervation via a direct effect on unmyelinated sensory nociceptor neurons and that estradiol, a well-documented therapeutic, may alleviate symptoms in part by reducing progesterone-induced sensory hyperinnervation.

Managing threats to femininity: personal and interpersonal experience of living with vulval pain

Women living with vulval pain can experience psychosocial difficulties. The current study explores the meaning and impact of vulval pain using interpretative phenomenological analysis. Interviews were conducted with eight women. Three overlapping super-ordinate themes emerged: (1) loss of femininity/sexual identity, (2) centrality of sex within relationships and (3) uncertainty surrounding the diagnosis. The participants here did not report the actual pain as being the central issue rather they felt the condition affected their sense of femininity, which was perceived in many ways as analogous to loss of sexual identity. Although they often avoided sexual contact, they also reported deep concern about the sexual needs of their partners and consequently often prioritised their partners, needs over their own in order to regain both their femininity and avoid anticipated rejection. The results indicate that the meaning the vulval pain had on the identity and relationships of the participants is the central concern in coping with this condition. These psychosocial factors need to be considered alongside existing medical management by health care professionals.

Neuromodulation of pelvic visceral pain: review of the literature and case series of potential novel targets for treatment

Chronic pelvic pain (CPP) is complex and often resistant to treatment. While the exact pathophysiology is unknown, the pain states resultant from conditions such as interstitial cystitis and the like yield patients with a presentation that bears a striking similarity to neuropathic syndromes that are known to respond to neuromodulation. While there has been past success using the sacral region as a target for spinal cord stimulation (SCS) to treat these patients, there remains to be a consensus on the optimal location for lead placement. In this article, the authors discuss the potential etiology of CPP, examine the current literature on lead placement for SCS as a method of treatment, as well as present several cases where novel lead placement was successfully employed.

Increased vanilloid receptor VR1 innervation in vulvodynia

Vulvodynia is characterised by painful burning sensation, allodynia and hyperalgesia in the region of the vulval vestibulus. While in many patients the cause of vulvodynia remains uncertain, we and others have previously shown increased intraepithelial and papillary innervation in vulvodynia. The vanilloid receptor VR1 (TRPV1) is expressed by nociceptors, and is triggered by capsaicin, noxious heat, protons, and chemicals produced during inflammation. In the present study we show increased papillary VR1 fibres by immunostaining and image analysis in vulvodynia tissues compared to controls (p<0.002). VR1 expression was found to be significantly increased when the percentage area immunostained was expressed as a ratio of VR1 to PGP 9.5, a pan-neuronal marker (P=0.01). VR1-positive fine epidermal fibres also appeared to be increased in vulvodynia tissues, by inspection. Fibres immunoreactive to the voltage-gated sodium channel SNS1/PN3 (Nav1.8), also expressed by nociceptors, were relatively scarce in both vulvodynia and control tissues. We hypothesize that increased expression of VR1 by nociceptors could mediate some of the symptoms in vulvodynia, for which systemic or topical specific VR1 antagonists may provide novel treatment.

Randomized trial of leuprolide versus continuous oral contraceptives in the treatment of endometriosis-associated pelvic pain

OBJECTIVE

To compare the efficacy of leuprolide and continuous oral contraceptives in the treatment of endometriosis-associated pain.

DESIGN

Prospective, randomized, double-blind controlled trial.

SETTING

Academic medical centers in Rochester, New York, and Boston, Massachusetts.

PATIENT(S)

Forty-seven women with endometriosis-associated pelvic pain.

INTERVENTION(S)

Forty-eight weeks of either depot leuprolide, 11.25 mg IM every 12 weeks with hormonal add-back using norethindrone acetate 5 mg orally, daily; or a generic monophasic oral contraceptive (1 mg norethindrone + 35 mg ethinyl estradiol) given daily.

MAIN OUTCOME MEASURE(S)

Biberoglu and Behrman (B&B) pain scores, numerical rating scores (NRS), Beck Depression Inventory (BDI), and Index of Sexual Satisfaction (ISS).

RESULT(S)

Based on enrollment of 47 women randomized to continuous oral contraceptives and to leuprolide, there were statistically significant declines in B&B, NRS, and BDI scores from baseline in both groups. There were no significant differences, however, in the extent of reduction in these measures between the groups.

CONCLUSION(S)

Leuprolide and continuous oral contraceptives appear to be equally effective in the treatment of endometriosis-associated pelvic pain.

Assessment of vulvodynia symptoms in a sample of U.S. women: a follow-up national incidence survey

OBJECTIVE

To estimate the annual incidence of vulvodynia-like symptoms and evaluate triggers of vulvar pain in a sample of U.S. women.

METHODS

After a 1-year interval, women who previously participated in a national vulvodynia prevalence study were recontacted and administered a telephone questionnaire that assessed self-reported vulvodynia-like symptoms and triggers of symptoms.

RESULTS

From the original cohort of 425 women, 285 (67%) participated in this follow-up study. Symptoms consistent with vulvodynia occurring within 1 year of initial contact were reported by 4.7% of previously asymptomatic women. Nearly 50% of the original patients again reported a history of vulvodynia-like symptoms, with 68.6% of these as persistent over the past year. Of significance, pain or discomfort with first-time tampon use was 2.15 times more likely (95% CI 1.0-4.62) in symptomatic women. These women were also 2.4 times more likely (95% CI 1.29-4.53) to use a combination of tampons and pads for sanitary protection rather than one method alone.

CONCLUSIONS

Over the course of 1 year, as many as 1 in 20 women may experience new-onset chronic genital pain. Despite a higher likelihood of having discomfort or pain with first tampon use, symptomatic women did not exhibit a preference for sanitary napkins. This indicates that lack of tampon use because of pain may not be an effective screening criterion for vulvodynia. We recommend additional studies with symptomatic and diagnosed women to explore in more detail the issues surrounding tampon use history and chronic genital pain.

How young does vulvo-vaginal pain begin? Prevalence and characteristics of dyspareunia in adolescents

INTRODUCTION

Dyspareunia remains under-investigated despite recent population-based studies indicating that its prevalence ranges from 12% to 21% in adult women. Although clinical data suggest that dyspareunia can begin during adolescence, a large-scale epidemiological study has yet to be conducted with this population.

AIMS

To determine the prevalence and characteristics of dyspareunia in a large-scale sample of adolescents, in addition to the characteristics of vulvo-vaginal insertion pain in nonsexual contexts.

METHODS

With written informed consent, data were obtained from 1,425 girls (12-19-year-olds), from seven metropolitan high schools during regular school hours using a self-report questionnaire.

MAIN OUTCOME MEASURES

Dyspareunia prevalence was evaluated by asking sexually active participants whether or not they regularly (at least 75% of the time) experienced pain during intercourse. Pain duration, context of onset, location, intensity, and pain during tampon insertion and pelvic exams were evaluated.

RESULTS

Results revealed that 20% of sexually active girls (N = 251) reported having regular pain during intercourse for at least 6 months or more. A primary form of pain was reported by 67% of adolescents and significantly more girls with chronic dyspareunia identified the vaginal opening (39%; x=3.9/10) as being their most painful site compared with internal pain sites (18-29%; x=2.9-3.2/10) (P = 0.042). Chronic dyspareunia cases reported significantly more pain during first and usual tampon insertion (P = 0.003; P = 0.009) than pain-free controls, while no difference was found between groups regarding pelvic exams (P = 0.086). Experiencing severe pain at first tampon insertion was linked to a fourfold risk of reporting chronic dyspareunia (P = 0.001).

CONCLUSIONS

Results mirror prevalence estimates found in population-based studies with adult women and suggest that chronic dyspareunia is a significant sexual health problem in adolescent girls, with pain extending beyond intercourse to nonsexual contexts.

[Review of the literature on the psychoemotional reality of women with vulvodynia: difficulties met and strategies developed]

BACKGROUND

Within the past three decades, increased attention has been placed on the study of vulvodynia -- an unexplained chronic vulvular discomfort felt without any related pathology. In addition to its physical implications, vulvodynia has a psychosocial dimension.

OBJECTIVE

The purpose of the current article is to present a review of the literature on the psychoemotional reality of women with vulvodynia.

METHOD

A systematic literature review was conducted in the main social sciences databases, such as Dissertation Abstracts, Current Contents and PsycINFO.

RESULTS

Although some discrepancies were found in study results, the review of the literature revealed that women with vulvodynia are often confronted with identity and psychological difficulties, which are, in turn, influenced by social standards regarding sexuality and femininity. To cope with these difficulties, women develop different strategies to decrease the stress related to pain and enhance their psychological well-being.

CONCLUSION

The psychological and relational difficulties experienced by women with vulvodynia are not only due to the physical pain but also to the meaning they attribute to it, often influenced by social expectations related to heterosexuality and femininity. Hence, it is important to assist these women by increasing their knowledge on the psychosocial aspects of their experience while taking into account influences from the social context.

Life events in patients with vulvodynia

OBJECTIVE

Vulval pain, in the absence of pathology, may have a psychological basis that relates to life events. This study aimed to determine the nature of such events.

DESIGN

Structured questionnaire about patient's symptoms and early-life events.

SETTING

Private practice physiotherapist specialising in pelvic floor disorders.

POPULATION

Patients with vulvodynia as their primary symptom and control patients being treated for urinary tract disorder or post-childbirth routine physiotherapy who had no vulval pain on direct questioning.

METHODS

Questionnaire applied to consecutive patients referred for treatment. Seventy-eight consecutive women presenting with vulvodynia (mean age 34 years, mean duration of symptoms 48 months) and 78 controls (mean age 39 years).

MAIN OUTCOME MEASURES

Incidence of life events.

RESULTS

A similar proportion of both groups were married. Being in a new relationship (P < 0.04), adverse current or previous relationships (39 versus 9%, P < or = 0.01), parental divorce (26 versus 9%, P < or = 0.001), history of termination of pregnancy, and adverse childbirth experiences (P < 0.04) were more common in patients than in controls. A history of sexual abuse was not more common in patients with vulvodynia compared with controls (13 versus 10%, P = not significant). Lack of libido was common in patients with vulvodynia (94 versus 29%, P < 0.0001).

CONCLUSIONS

Adverse life experiences, including conflict, are common in women with vulvodynia. These factors may be important in mediating the genesis of pain through stress-related mechanisms. Sexual interest is diminished in these women. Sexual abuse is not a factor in most of these women. These findings have implications for treatment.

Vulvodynia: a psychophysiological profile based on electromyographic assessment

The objective of this study was to explore the relationship between psychological and physiological processes and how these interact in the case of vulvodynia. The study design consisted of a retrospective review of predominantly premenopausal women presenting with vulvodynia via analyses of questionnaires, psychometric tests, sexual history, surface electromyographic (sEMG) assessments, and clinical notes. Five hundred and twenty-nine patients with vulvodynia (mean age 27.7 years) were studied. The average age of symptom onset was 22.8 years and the average duration of symptoms was 5.0 years. Patients scored higher than the comparison group on global dimensions of the Symptom Checklist-90 Revised (SCL-90R), with anxiety and depression scores showing a significant but modest correlation with severity of pain. sEMG data confirmed an association with pelvic muscle dysfunction but there was no correlation with severity of vulvar pain. A negative correlation between sEMG readings and duration of pain was noted and may be due to progressive time-related quieting of electrical activity in muscle tissues, which is commonly associated with the development of a functional muscle contracture. In conclusion, it is important to view chronic pain syndromes like vulvodynia from a psychophysiological perspective which recognizes the potential contribution of psychological and physiological variables in the aetiology of chronic vulvar pain.

The impact of chronic vulval pain on quality of life and psychosocial well-being

BACKGROUND

Chronic or recurrent pain associated with the female reproductive system is not well understood and has been neglected in research, despite it being a costly health problem.

AIMS

The present research investigated the psychosocial impact of vulval pain on health-related quality of life, sexual well-being, and relationship satisfaction among Australian women.

METHODS

Between June and December 2004, Australian women with and without vulval pain completed a questionnaire containing a range of well-validated self-report measures. Questionnaires were returned by 51 women aged between 19 and 68 years with vulval pain and 46 women aged between 21 and 65 years without vulval pain.

RESULTS

Similar to previous research, Australian women with vulval pain reported significantly worse health-related quality of life, higher levels of distress related to sexual activities, and lower levels of happiness in couple relationships than those without pain.

CONCLUSIONS

These results highlight serious psychosocial implications for women experiencing chronic vulval pain. Understanding the impact that vulval pain has on women may assist in developing appropriate psychosocial interventions that may improve quality of life.

A Conceptual Model for the Pathophysiology of Vulvar Vestibulitis Syndrome

Vulvar vestibulitis syndrome (vestibulitis), the most common type of chronic vulvovaginal pain, impairs the psychologic, physical, and reproductive health of approximately 10% of women at some point in their lives. Research on the pathophysiology of vestibulitis suggests abnormalities in 3 interdependent systems: vestibular mucosa, pelvic floor muscles, and central nervous system pain regulatory pathways. To date, causes and relative contributions of these abnormalities to the development and maintenance of vestibulitis remain poorly understood. Research consistently supports the conceptualization of vestibulitis as a chronic pain disorder-akin to fibromyalgia, irritable bowel disorder, and temporomandibular disorder (TMD)-that is far more complex than vestibular hypersensitivity alone. Nevertheless, the clinical diagnosis of vestibulitis continues to rely on subjective report of pain during intercourse and vestibular sensitivity on clinical examination after exclusion of other gynecologic disorders. We propose that current diagnostic criteria, which are based on highly subjective patient and clinician measures, are not sufficient to describe and properly classify the heterogeneous clinical presentations of this disorder. To inform clinical care or research, we must be able to objectively characterize women with vestibulitis. This narrative review critically appraises current conceptualization of vestibulitis and presents a context for studying vestibulitis as a chronic pain disorder, emphasizing the need for objective assessment of clinical features.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to state that vulvar vestibulitis is common; recall that the disorder has three major pathophysiological pathways and that understanding of these pathways is important in selecting treatment options, and explain that the clinician must attempt to properly classify the clinical presentations of the disorder.

Psychological factors associated with perception of experimental pain in vulvar vestibulitis syndrome

This study assessed the association between pain perception and psychological variables in women with vulvar vestibulitis syndrome (VVS) by comparing 28 VVS women with 50 healthy women. We assessed non genital systemic pain perception with quantitative sensory testing by administering experimental pain stimuli to the forearm. The VVS women demonstrated a lower pain threshold and a higher magnitude estimation of pain, combined with a higher trait anxiety, increased somatization, and a lower body image. Among the VVS women, nonvaginal pain catastrophizing was significantly related to reported pain during coitus. A cluster analysis revealed four subtypes of VVS women, as characterized by levels of pain and personality variables. I suggest implications for the assessment and treatment of women suffering from painful coitus.

A multidimensional, case-control study of women with self-identified chronic vulvar pain

OBJECTIVE

The purpose of the present study was to conduct a multidimensional evaluation of women with chronic vulvar pain.

DESIGN

Fifty-seven women with self-identified vulvar pain were contrasted with 74 healthy control women. Measures were selected based on a multidimensional perspective and included questionnaires related to the core aspects of chronic pain: Pain severity, physical disability, affective distress, and marital satisfaction.

RESULTS

In comparison with controls, women with vulvar pain reported significantly greater physical disability and affective distress. In women with vulvar pain, pain severity was not related to physical disability and affective distress. While women with vulvar pain scored in the normal range for marital satisfaction, they reported significantly less marital satisfaction than controls.

CONCLUSIONS

Findings suggest that the experience of persistent vulvar pain in general, rather than the level of intensity of the pain, accounts for disturbances in functioning and emotional well-being. In comparison with their peers, but not with norms, women with vulvar pain reported less marital satisfaction. A multidimensional approach to the assessment of chronic vulvar pain will lead to a greater understanding of the psychosocial functioning of women with this condition.

Personality traits associated with perception of noxious stimuli in women with vulvar vestibulitis syndrome

Vulvar vestibulitis syndrome (VVS) is associated with enhanced pain sensitivity. The present study explores the role of personality on the perception of noxious stimuli among women with VVS. More specifically, the aim of the study was to explore whether the personality traits assessed by Cloninger's Tridimensional Personality Questionnaire (TPQ) (harm avoidance [HA], novelty seeking [NS], and reward dependence [RD]) are associated with the augmented pain perception in women with VVS. Quantitative sensory tests were applied to the forearm of 98 women with VVS and 135 control subjects, all of whom completed the TPQ. The women with VVS scored higher than the control subjects on HA and RD with no significant differences in NS. Linear regression analyses revealed that in the VVS group, lower pain thresholds and higher magnitude estimations of suprathreshold pain stimuli were associated with higher HA and RD scores. The enhanced pain perception among women with VVS might reflect their tendency to respond intensely to signals of reward and to elevate the perceived risk. This might lead them to avoid hazards by overestimating the level of potential harm, as represented by greater pain sensitivity. The association between personality traits assessed by Cloninger's Tridimensional Personality Questionnaire, ie, harm avoidance, novelty seeking, and reward dependence, and the enhanced perception of noxious stimuli in vulvar vestibulitis syndrome might suggest neurochemical mechanisms of pain experience affected by personality, with possible application for future treatment approaches toward pain disorders.

On the Reliability and Validity of Physician Ratings for Vulvodynia and the Discriminant Validity of its Subtypes

OBJECTIVE

This study aimed to test the reliability and validity of physician ratings in a broadly defined sample of women with vulvodynia and to examine the external validity of the vulvodynia subtypes.

DESIGN

Participants were 50 women who were independently diagnosed with vulvodynia by two study gynecologists. Physician ratings corresponding to Friedrich's three criteria for vulvar vestibulitis were taken at the two examinations. Each participant's diagnosis was subtyped as vulvar vestibulitis (VV) or dysesthetic vulvodynia (DV) based upon the physician ratings. Participants completed standardized measures of pain, sexual function, psychological function, and quality of life to examine the discriminant validity of the subtypes.

RESULTS

Test-retest reliability for the physician ratings of Friedrich's three criteria was stable for two of the three criteria (i.e., pain on attempted vaginal entry and tenderness to pressure localized within the vulvar vestibule). When these criteria were used to categorize participants as having VV or DV, the subtypes were not statistically different for measures used to examine the discriminant validity of the subtypes. While the distribution of patients changed when premenopausal state was added to the inclusion criteria for VV, the subtypes differed little on the outcome measures.

CONCLUSIONS

Findings from the present study suggest that physician ratings for Friedrich's criteria can be operationalized and found to be reliable and valid in a wide range of women with vulvodynia. The absence of differences between subtypes on measures of pain, sexual function, psychological function, and quality of life challenge the clinical significance of these subtypes and support the theory that vulvodynia represents a continuum of chronic vulvar pain rather than two distinct entities.

Estrogen Regulates Vaginal Sensory and Autonomic Nerve Density in the Rat1

Vaginal function is strongly influenced by reproductive hormone status. Vaginal dysfunction during menopause is generally assumed to occur because of diminished estrogen-mediated trophic support of vaginal target cells. However, peripheral neurons possess estrogen receptors and are potentially responsive to gonadal steroid hormones. In the present study, we investigated whether sensory and autonomic innervation of the vagina varies among rats during the estrus phase of the estrous cycle, following chronic ovariectomy, and after sustained estrogen replacement. Relative to rats in estrus, ovariectomized rats showed a 59% elevation in nerve density, as determined using the panneuronal marker PGP 9.5. This increase persisted even after correcting for differences in vaginal tissue size, indicating true axonal proliferation after ovariectomy rather than changes secondary to altered volume. Increased total innervation after ovariectomy was attributable to increased densities of sympathetic nerves immunostained for tyrosine hydroxylase (70%), cholinergic parasympathetic nerves immunoreactive for vesicular acetylcholine transporter (93%), and calcitonin gene-related peptide-immunoreactive sensory nociceptor nerves (84%). Myelinated primary sensory innervation revealed by RT-97 immunoreactivity did not appear to be affected. Sustained 17beta-estradiol administration reduced innervation density to an extent comparable to that of estrus, implying that estrogen is the hormone mediating vaginal neuroplasticity. These findings indicate that some aspects of vaginal dysfunction during menopause may be attributable to changes in innervation. Increased sympathetic innervation may augment vasoconstriction and promote vaginal dryness, while sensory nociceptor axon proliferation may contribute to symptoms of pain, burning, and itching associated with menopause and some forms of vulvodynia.

Primary and secondary vulvar vestibulitis syndrome: systemic pain perception and psychophysical characteristics

OBJECTIVE

Women with primary and secondary vulvar vestibulitis syndrome (VVS) report similar vulvar pain symptoms; however, it is not clear whether these subsets have similar pain and psychophysical characteristics. This study evaluated systemic pain perception, cardiovascular measures, and anxiety level in women with primary and secondary VVS.

STUDY DESIGN

Eighty-nine women were enrolled in the study: 44 had primary vulvar vestibulitis, 45 had secondary vulvar vestibulitis. Their anxiety level was first assessed. Then, heat pain stimuli were applied to the forearm, and pain threshold and pain scores for suprathreshold phasic (44 degrees C-48 degrees C) and tonic (46 degrees C) stimuli were assessed by visual analog scale. Finally, blood pressure was recorded using a volume clamp method before, during, and after a tonic stimulus of 1 minute at 46 degrees C.

RESULTS

Women with primary vulvar vestibulitis had higher visual analog scale scores for pain perception at 46 degrees C to 48 degrees C, a higher level of trait anxiety 43.3 +/- 1.5 versus 37.8 +/- 1.5 (P=.010), an increased incidence of dysmenorrhea (chi(2) 8.9, P=.003), and lower resting blood pressure: systolic (108.6 +/- 2.1 vs 118.9 +/- 2.0 mm Hg) (P>.001) and diastolic (59.3 +/- 1.6 vs 64.2 +/- 1.5 mm Hg) (P=.038). Logistic regression revealed that dysmenorrhea and lower systolic blood pressure are associated with primary VVS.

CONCLUSION

Women with primary and secondary VVS differ in their systemic pain perception and psychophysical characteristics. The impact of these findings on treatment modalities should be further evaluated.

Association between quantitative sensory testing, treatment choice, and subsequent pain reduction in vulvar vestibulitis syndrome

The chronic pain syndrome of vulvar vestibulitis is a major cause of sexual dysfunction, and complete cure is not always achieved. The aim of the study was to determine whether the psychophysical characteristics of systemic pain perception predict treatment choice and outcome. Ninety women with vulvar vestibulitis syndrome were evaluated by using quantitative sensory testing with heat pain threshold measurements and pain scores for suprathreshold stimuli applied to the forearm, blood pressure measurements, and an assessment of the number of other pain disorders. Women were free to choose a surgical procedure (ie, vestibulectomy), one of the possible nonsurgical treatments (eg, biofeedback, cognitive-behavioral therapy, or hypoallergic agents), or to avoid treatment entirely. Eight months later, women reported the success of the treatment on the basis of reduction in the level of vulvar pain. Vestibulectomy demonstrated the best therapeutic effectiveness (chi2, 26.4; P <.0001). Women who chose this type of treatment had lower pain scores (P =.038) and fewer pain syndromes other than the vulvar pain (P =.025). Logistic regression analysis, controlling for the effect of vestibulectomy, indicated that lower experimental pain scores (P =.044), fewer pain disorders (P =.023), and higher systolic blood pressure (P =.039) are predictive variables for reduction of vulvar pain. An assessment of systemic pain perception might be helpful in choosing the optimal treatment and in predicting its success.

PERSPECTIVE

The present study suggests that pain perception variables might be of value in the prediction of treatment choice and outcome among women with vulvar vestibulitis.

Sacral neuromodulation for chronic pain conditions

Some of the pelvic pain syndromes seem to have features of neurogenic inflammation and neuropathic pain in common. As opposed to being separate disease entities, they may represent a spectrum of clinical presentations of CRPS I of the pelvis. Sacral nerve root stimulation provides good symptomatic relief of pain and voiding dysfunction. The techniques of retrograde root stimulation may offer superior results with fewer complications and lead migrations when compared with other methods. Perhaps neuromodulation should be used earlier in the treatment paradigm for these disorders, before the potentially injurious procedures of hydrodistention, bladder installations, and cystectomies.

Management of vulvar pain

Vulvodynia is a frequently used medical term that literally means "vulvar pain". Therefore, vulvodynia is a symptom, not a disease. The term itself indicates a variety of unpleasant chronic vulvar sensations, including burning, rawness, soreness, irritation, sensitivity, and formication. This may or may not include dyspareunia. Primary vulvodynia occurs when these sensory disturbances occur in the absence of observable dermatologic disease or vulvovaginal infection. There are several causes for this, including neuropathy, referred pain, and pelvic floor muscle dysfunction. For the purist, it is the patient in whom there is no observable reason for vulvar pain who represents the true case of vulvodynia. However, vulvodynia can also occur secondarily as a symptom of vulvar skin disease. Restricting the present paper to patients without objective signs leaves out all the important conditions which come into the differential diagnosis of vulvar pain which should be ruled out first. The first step in managing vulvodynia is making an accurate diagnosis of its cause. The present review summarizes the diagnosis and management of the chronic dermatologic diseases which may cause primary and secondary vulvodynia. The etiology of primary vulvodynia is much more poorly understood than secondary vulvodynia, and treatment of some aspects remains controversial.

Vulvar vestibulitis severity—assessment by sensory and pain testing modalities

Vulvar vestibulitis syndrome (VVS) is a common cause of dyspareunia in pre-menopausal women. Previous quantitative sensory test (QST) studies have demonstrated reduced vestibular pain thresholds in these patients. Here we try to find whether QST findings correlate to disease severity. Thirty-five vestibulitis patients, 17 with moderate and 18 with severe disorder, were compared to 22 age matched control women. Tactile and pain thresholds for mechanical pressure and thermal pain were measured at the posterior fourcette. Magnitude estimation of supra-threshold painful stimuli were obtained for mechanical and thermal stimuli, the latter were of tonic and phasic types. Pain thresholds were lower and supra-threshold magnitude estimations were higher in VVS patients, in agreement with disease severity. Cut-off points were defined for results of each test, discriminating between moderate VVS, severe VVS and healthy controls, and allowing calculation of sensitivity and specificity of the various tests. Our findings show that the best discriminative test was mechanical pain threshold obtained by a simple custom made 'spring pressure device'. This test had the highest kappa value (0.82), predicting correctly 88% of all VVS cases and 100% of the severe VVS cases. Supra-threshold pain magnitude estimation for tonic heat stimulation also had a high kappa value (0.73) predicting correctly 82% overall with a 100% correct diagnosis of the control group. QST techniques, both threshold and supra-threshold measurements, seem to be capable of discriminating level of severity of this clinical pain syndrome.

Psychological profiles among women with vulvar vestibulitis syndrome: a chart review

The purpose of this study was to assess the prevalence and type of psychological distress in women with vulvar vestibulitis syndrome (VVS). A retrospective chart review was conducted of all women receiving a diagnosis of VVS referred to a tertiary care facility during a two-year period. Brief psychological questionnaires, including the Personality Assessment Screener, Fear of Negative Evaluation Scale, Golombok-Rust Inventory of Sexual Satisfaction, and the Phobia Rating Scale were administered. Fifty-consecutive cases were reviewed along with 12-15 month follow-up data for 41 cases. Phobic anxiety to vaginal touch or entry was significantly higher in women with VVS than normative data. Fear of Negative Evaluation was a strong associated feature, and for 30% approached clinically significant levels. Twenty-six percent showed a moderate, while another 26% showed a mild clinically distressed profile. Negative affect and social withdrawal were among the most frequently endorsed variables. Improvement in allodynia and intercourse were both related to these psychological variables, and a multiple regression analysis supported the use of psychological instruments in addition to standard medical assessment. A subgroup of women with VVS display clinically significant broad based psychological distress that warrants additional assessment. The use of psychological questionnaires in addition to medical assessment of women with VVS may provide valuable information predictive of treatment needs and response.

Management of common vulval conditions

Community-based surveys indicate that about a fifth of women have significant vulval symptoms lasting over three months at some time in their lives. Common causes of itch or pain are dermatitis, recurrent candidiasis and the recently recognised pain syndromes--vulvar vestibular syndrome and dysaesthetic vulvodynia. Diagnosis is usually apparent after a thorough history and examination, although conditions commonly coexist and are complicated by prior treatment. Skin lesions not responding to treatment require biopsy. Treatment aims to control symptoms rather than to cure; avoiding soaps and other irritants is central to management. An early, accurate diagnosis should enhance management of vulval conditions, particularly pain syndromes.

Enhancement of the perception of systemic pain in women with vulvar vestibulitis

OBJECTIVE

The aim of this study was to determine whether the characteristics of systemic pain perception and anxiety differ between women with vulvar vestibulitis and healthy women.

DESIGN

Case control study.

SETTING

Tertiary care hospital.

POPULATION

Forty-four women with vulvar vestibulitis and 41 healthy women participated in the study.

METHODS

First, the women's state and trait anxiety was evaluated. Thereafer, heat pain stimuli were applied to the women's forearm and the pain and unpleasantness thresholds, as well as magnitude estimation of perceived intensity and unpleasantness of suprathreshold stimuli, were assessed. Finally, blood pressure was measured before, during and after a heat stimulus of 46 degrees C.

MAIN OUTCOME MEASURES

Pain threshold and suprathreshold, and anxiety levels of women with vulvar vestibulitis.

RESULTS

Women with vulvar vestibulitis had a higher anxiety state (40.0 [12.8] vs 34.1 [10.8], P = 0.044), a higher anxiety trait (42.1 [10.2] vs 35.6 [7.5], P = 0.005), a lower pain threshold (42.2 degrees C [2.5] vs 43.6 degrees C [1.9], P = 0.006), a lower unpleasantness threshold (40.2 degrees C [2.9] vs 41.7 degrees C [2.3], P = 0.023), a higher magnitude estimation of suprathreshold pain at 47 degrees C (88.3 [14.9] vs 70.8 [14.9], P = 0.0001) and at 48 degrees C (96.1 [7.3] vs 84.6 [14.8], P < 0.0001), a higher scoring of tonic pain perception (65.2 [17.3] vs 53.0 [18.6], P = 0.006) and a higher increase in systolic blood pressure during tonic pain stimuli (4.6 [9.6] vs -2.1 [8.7] mmHg, P = 0.005).

CONCLUSION

Women with vulvar vestibulitis have an enhanced systemic pain perception and are more anxious.

Vestibular tactile and pain thresholds in women with vulvar vestibulitis syndrome

Vulvar vestibulitis syndrome (VVS) is a common cause of dyspareunia in pre-menopausal women. Little is known about sensory function in the vulvar vestibule, despite Kinsey's assertion that it is important for sexual sensation. We examined punctate tactile and pain thresholds to modified von Frey filaments in the genital region of women with VVS and age- and contraceptive-matched pain-free controls. Women with VVS had lower tactile and pain thresholds around the vulvar vestibule and on the labium minus than controls, and these results were reliable over time. Women with VVS also had lower tactile, punctate pain, and pressure-pain tolerance over the deltoid muscle on the upper arm, suggesting that generalized systemic hypersensitivity may contribute to VVS in some women. In testing tactile thresholds, 20% of trials were blank, and there was no group difference in the false positive rate, indicating that response bias cannot account for the lower thresholds. Women with VVS reported significantly more catastrophizing thoughts related to intercourse pain, but there was no difference between groups in catastrophizing for unrelated pains. Pain intensity ratings for stimuli above the pain threshold increased in a parallel fashion with log stimulus intensity in both groups, but the ratings of distress were substantially greater in the VVS group than in controls at equivalent levels of pain intensity. The data imply that VVS may reflect a specific pathological process in the vestibular region, superimposed on systemic hypersensitivity to tactile and pain stimuli.