Vulvar Vestibulitis Syndrome
Following numerous yeast infections after using a new oral contraceptive pill 2 years ago, Sandra, a 25-year old primary school teacher, started experiencing an intense burning pain at the entrance of her vagina during sexual intercourse. The pain started with initial penetration, lasted throughout intercourse, and was present for 30 min afterwards. Thinking that it was caused by yet another yeast infection, Sandra purchased her usual treatment from the pharmacy: over-the-counter antifungal vaginal suppositories. However, this only increased her pain to the point that, 6 months later, she had become apprehensive about sexual activity with her long-term partner. She also noticed a “tensing up” of her pelvic floor muscles while engaging in foreplay and a marked decrease in her sexual desire and arousal levels, which further contributed to her pain. Sandra began avoiding all sexual activities, even nonpenetrative ones. She sought treatment from several medical professionals, underwent several painful examinations, and tried various topical creams and lubricants without any improvement in her pain or answers as to what her pain was. She began doubting her love for her partner, thinking that the pain was indicative of relationship problems. Finally, through one of her friends at work, Sandra obtained the phone number of a gynecologist who diagnosed her with vulvar vestibulitis syndrome and recommended physical therapy and pain relief therapy.
Friedrich (6) proposed the following diagnostic criteria for vulvar vestibulitis: (1) severe pain upon vestibular touch or attempted vaginal entry, (2) tenderness to pressure localized within the vulvar vestibule, and (3) physical findings limited to vestibular erythema of various degrees. Although the third criterion has not received much support in terms of its validity and reliability, the first two have (14). Typically, vestibulitis patients present with provoked pain at the entrance of the vagina, their main complaint usually being painful intercourse. The cotton-swab test, a standard gynecological tool for diagnosing vestibulitis, consists of the application of a swab to various areas of the genital region. If the woman reports pain when pressure is applied to the vestibule during this test, then the diagnosis of vestibulitis is made. The cotton-swab test is usually performed in a clockwise manner around the vestibule; however, research has shown that pain ratings increase with each successive palpation. Therefore, we recommend a randomized order of cotton-swab application with adequate pauses after each palpation to avoid sensitization of the vulvar vestibule and unnecessary pain to the patient (16,20).
Although the cotton-swab test for the diagnosis of vulvar vestibulitis syn- drome is considered the clinical method of choice since it is fast and easy to perform, it is not necessarily the standard tool for research purposes. First, the amount of pressure applied during the cotton-swab test is not standardized either between or within gynecologists (16,20,21). Indeed, it has been shown that different gynecologists apply different pressures and can elicit significantly different pain ratings in the same women (16,20). Second, the amount of pressure applied using this method are above pain threshold level, that is, the point at which women report the first sign of pain, making the cotton-swab test highly painful and distressing for patients. In order to overcome these problems, Pukall et al. (20) have developed a device called a vulvalgesiometer, which holds much promise in terms of standardized genital pain measurement by allowing for the application of known pressures using a spring-based device. The vulvalgesiometer replicates the quality of pain that women with vulvar vestibulitis report experiencing during intercourse, and is currently being used in numerous studies.
Joanne, a 39-year-old lawyer, reported a constant tingling and burning sensation over her entire vulvar area, including her labia, perineum, vestibule, and clitoris, for the past 3 years. The sensations started progressively, initially with short periods of discomfort, but gradually became more frequent and intense to the point that she always felt some degree of pain during a 24-h period. The pain increased sharply with both sexual and nonsexual activities (e.g., walking or sitting for long periods of time), but she sometimes experienced these increases without provocation. She, like Sandra, underwent many invasive examinations and received numerous treatments, none of which helped. Joanne found that all aspects of her life were negatively affected; she had difficulties working, sleeping, and engaging in sexual activities. The pain was always on her mind, and although she obtained some relief from applying ice packs wrapped in towels to her vulva, this solution was only temporary and limited to her home environment. She lost interest in sex and began reducing her sexual activities, as they would exacerbate her pain. Desperate, she waited 1 year on a waiting list at a chronic pain service and was finally diagnosed with vulvodynia. She was prescribed a low dose of Elavil to help her sleep and to decrease the amount of pain she was experiencing, and was given a recommendation to join a vulvodynia support group to learn more about her condition and to meet others who experienced difficulties similar to hers.
The diagnosis of vulvodynia is a diagnosis of exclusion, meaning that other causes for the pain (e.g., infections, inflammation, postherpetic neuralgia) must be ruled out, as in the case of vulvar vestibulitis syndrome. It is based on the description, quality, and location of the pain. Vulvodynia sufferers report chronic vulvar discomfort characterized by a burning sensation that is not contact-dependent. The pain is diffuse, often covering the vulvar area and includ- ing the perineum and may or may not lead to dyspareunia. Some vulvodynia sufferers also meet the diagnostic criteria for vulvar vestibulitis syndrome. It is crucial to rule out pruritus vulvae, which affects the same region as vulvodynia but is characterized by an itching sensation, and is often associated with skin changes, including excoriation and erythema (13,22). In addition, pudendal neu- ralgia must also be ruled out. In this condition, pain radiates from the vulva to the rest of the perineum, groin, and/or thighs and hyperesthesia is present in a saddle distribution. McKay (13) recommends the following evaluation for vulvodynia: examination of the skin for dermatoses and a careful search for infectious agents likely to cause inflammation. This is followed by nerve assessment, and by a careful anatomic distribution of involved areas, as locations and patterns of discomfort have been shown to be important in differential diagnosis (13).
Brenda (age 55) and Alexander (age 57) had been married for 30 years when they were referred to a sex and couple therapy clinic for dyspareunia by her gyneco- logist. A comprehensive pain assessment revealed that Brenda experienced a “rubbing, cutting, and sometimes burning” pain upon penetration and a deeper “dull, pulling pain” during intercourse. She reported that the pain started 4 years ago, at a time when she began to experience hot flashes and irre- gular periods, with an increase in intensity of the superficial pain over the last year. Attempts to lessen the pain through the use of water-based lubricants and topical estradiol cream had not been successful, and she did not wish to try sys- temic hormone replacement therapy for fear of developing breast cancer. A detailed sexual history revealed that Brenda had suffered from intermittent pain during intercourse for at least 15 years but had never complained about it, and that Alexander had always had difficulties with ejaculatory control. Over the past 4 years, Brenda reported difficulty getting sexually aroused, dimin- ished lubrication, postcoital bleeding, and less interest in sex. Their current sexual frequency was less than once every 3 months, a frustrating situation for Alexander, who had hoped that their youngest child leaving home in the previous year would result in more frequent sexual activity. In the previous 5 years, the couple had also experienced significant life stressors including the sudden death of Brenda’s mother and major financial problems. The couple was seen in therapy to help overcome their sexual difficulties, to manage the pain, and to receive support and advice concerning their stressful life situation.
As women approach middle-age and menopause, physiological aging, psychosocial factors, and declining levels of endogenously produced sex hormones caused by ovarian senescence can exert significant effects on their sexual response cycle. As such, comprehensive enquiry of dyspareunic pain characteristics and history, cli- macteric symptoms, as well as changes in sexual functioning, urogenital anatomy, marital/partner relations that have occurred are essential in the assessment of post- menopausal dyspareunia. The many anatomical changes, within but not limited to the urogenital region, experienced by aging women (e.g., reduced vaginal and/or clitoral size, loss of fat and subcutaneous tissue from the mons pubis, arteriosclero- sis) can result in decreased sexual arousal, vaginal dryness, and dyspareunia (23). Dyspareunia may also result from iatrogenic efforts, including pelvic or cervical surgery and radiotherapy, and pharmacotherapy (24). Moreover, it is considered a secondary symptom of atrophic vaginitis, often accompanied with postcoital bleeding (25). Physical examination following reliable criteria such as the Vaginal Atrophy Index (26), hormonal assays, and cytological evaluation (i.e., pap smear) are essential in the diagnosis of vulvovaginal atrophy.
Psychosocial difficulties that commonly affect postmenopausal women may impinge on sexual functioning and affect pain perception. Intrapersonal issues, such as negative perceptions of menopause, body image, and postrepro- ductive sexuality, often function as self-fulfilling prophecies and foster sexual dysfunction in the menopause (27). Interpersonal factors such as marital/ relationship difficulties, partner’s sexual dysfunction (e.g., erectile dysfunction, decreased desire), and loss of social support may also be implicated (28). Clini- cians should carefully assess for possible non-biomedical factors that may play a role in maintaining postmenopausal dyspareunia before making a diagnosis or prescribing treatment.
Vulvar Vestibulitis Syndrome
Vulvar vestibulitis syndrome is believed to be the most common form of painful intercourse in premenopausal women (10), affecting an estimated 12% in the general population (8). Women with vulvar vestibulitis typically experience a severe sharp, burning pain localized at the entrance of the vagina (i.e., the vulvar vestibule) (14). This pain occurs upon contact, through both sexual and nonsexual stimulation (10,14). Approximately half of the women with vulvar vestibulitis syndrome have “primary” vestibulitis, that is, they have experienced the pain from their first intercourse attempt, whereas the other half of the sufferers develop the pain after a period of pain-free intercourse, termed “secondary” vestibulitis (29,30).
Characteristics of the Vulvar Vestibule in Affected and
To answer the question of what causes vulvar vestibulitis, it is necessary to start with where the vulvar vestibule is located and its normal tissue characteristics. The vulvar vestibule (Fig. 10.1) is a part of the external genitalia (i.e., the vulva). It extends from the inner aspects of the labia minora to the hymen, is bordered anteriorly by the clitoral frenulum and posteriorly by the fourchette, and includes the vaginal and urethral openings (31). The vestibule is innervated by the pudendal nerve (32) and contains free nerve endings, the majority of which are believed to be C-fibers, otherwise known as pain fibers (33). Although the vulvar vestibule is composed of visceral tissue, it has a nonvisceral innervation
Figure 10.1 The vulva. Parts of the vulva are shown, including the vulvar vestibule (indicated by dotted lines), clitoris, urethral and vaginal openings, and the labia majora and minora. The vulvar vestibule extends laterally from the base of the labia minora, and is bordered anteriorly by the clitoral frenulum and posteriorly by the fourchette. [Image courtesy of Katherine Muldoon.]
(34). Therefore, sensations of touch, temperature, and pain are similar to those evoked in the skin.
The suffix “-itis” refers to conditions of inflammatory origin and, in the case of vulvar vestibulitis, implies that the pain is due to an inflammation of vestibular tissue. However, studies examining indices of inflammation in this tissue suggest that inflammatory infiltrates are common in the vestibule, and thus, not necessarily related to the pain (35,36). Other controlled investigations of vestibular tissue suggest that altered pain processing plays a role in the devel- opment and/or maintenance of vulvar vestibulitis. Evidence for this includes the following: a heightened innervation of intraepithelial nerve fibers (33,37), an increase in blood flow and erythema (38), nociceptor sensitization (39), the pre- sence of calcitonin gene-related peptide (i.e., a peptide that exists in pain nerves) (40), and lower pain thresholds (41). These tissue properties would lead to an increase in sensation in response to vestibular pressure, consistent with the clini- cal picture of provoked pain in women with vestibulitis. Taking a cotton-swab, for example, and touching different areas of the vestibule in a non-affected woman is perceivable but not painful, but this same stimulation in the vestibule of a vestibulitis sufferer is perceived as excruciatingly painful.
Etiological Theories: Physical Explanations for the Pain
Yeast infections: Many etiological theories exist regarding what initiates the increase in sensitivity of the vulvar vestibule in sufferers (42,43). One of the most consistently reported findings associated with the onset of vulvar vestibuli- tis is a history of repeated yeast infections (44). However, it is not clear whether the culprit is the yeast itself or treatments undertaken which can sensitize the ves- tibular tissue or an underlying sensitivity already present in the tissue (29,45,46). Many women, like Sandra, when they feel the irritation during intercourse do not go to the doctor’s office to have a culture taken before they treat what they think is a yeast infection with over-the-counter remedies from the local drugstore. At the same time, some gynecologists may not perform the culture themselves, and on the basis of symptomatic description alone, suggest to the woman that she has a yeast infection (47). It is vital that both the woman and her health care pro- fessional ensure that treatment is not being undertaken without reason, as this can aggravate the problem.
Hormonal factors: Hormonal factors have also been found to be associ- ated with vestibulitis in controlled studies. Bazin et al. (30) and Bouchard et al. (48) found that women who used oral contraceptives had an increased risk of developing vestibulitis later in life, with those starting before the age of 16 being especially at risk. Early menarche (i.e., before the age of 11) and painful menstruation were also associated with an increased risk of vestibulitis (8,30). These findings suggest that hormonal factors may play a role in the increase in sensitivity of the vulvar vestibule, but the question of how hormones are involved remains to be elucidated.
Genetic factors: In one controlled study, Jeremias et al. (49) found that affected women have a high incidence of a genetic allele that is involved in the regulation of inflammation and is associated with chronic inflammatory con- ditions (e.g., ulcerative colitis, inflammatory bowel disease) (50,51). It is possible that women with this allele are genetically susceptible to the development of vestibulitis, but may only develop it after some injury to the vulvar vestibule, whether through repeated infections, local treatments, hormonal factors, early age at first intercourse, early age at first tampon use, and/or difficulty with or pain during first tampon use (8,9,30). Although these findings need to be repli- cated, they lead to several possible explanations for the development of vulvar vestibulitis. For example, women with this particular gene profile may have an abnormality in the regulation of inflammation, which has recently been shown in vestibulitis sufferers (52 – 54). This would allow vulvar vestibulitis to be one of many expressions of this gene; others would include colitis and inflammatory bowel disease. In addition, it would imply that women with vulvar vestibulitis might have associated pain problems and/or sensory abnormalities. Although just beginning to be examined, controlled studies support this implication. Women with vulvar vestibulitis have a higher sensitivity to vestibular touch (41), a higher sensitivity to nonvestibular touch, painful pressure, and heat pain (41,55), in addition to more somatic pain-related complaints (41,56) when compared with non-affected women.
Other factors: Many other physically based etiological theories of vulvar vestibulitis exist; however, they are based on uncontrolled studies and should be interpreted with caution. These include human papillomavirus infec- tion (57), faulty immune system functioning/allergies (6,58), urethral conditions (e.g., interstitial cystitis) (59), vaginismus (46), sexual abuse (44,60), and psycho- logical factors (e.g., somatization disorder) (46). It is important to note that controlled studies of sexual abuse (10,12) show no difference between affected and non-affected women, although a history of depression and physical abuse has been linked to vulvar vestibulitis (8). Furthermore, an increase in pelvic floor muscle tension (61,62) has also been associated with vulvar vestibulitis. Although the tensing of pelvic floor musculature may represent a protective reac- tion against, or a conditioned response to vulvar pain, this increase in tension is likely to only exacerbate the pain.
Etiological Theories: Psychosocial Explanations for the Pain
Psychological and cognitive factors: In accordance with current chronic pain models, there is much more to the experience of dyspareunia than the pain and its possible physiological underpinnings. This point is illustrated by a recent functional magnetic resonance imaging study of women with vulvar vestibulitis (63), demonstrating that both sensory and affective brain areas are activated in response to painful genital stimulation. These findings are consistent with results from other pain imaging studies (64 – 67) and support the multidimen- sional conceptualization of dyspareunia proposed in this chapter.
Factors such as psychological distress, anxiety, depression, low sexual self- esteem, harm avoidance, somatization, shyness, and pain catastrophization (41,55,56,60,68,69) have been found in women with vulvar vestibulitis. Whether they precede or develop subsequent to the pain remains to be elucidated; however, it is crucial to investigate the role of these factors in the maintenance of dyspareunia as negative affect has been shown to modulate pain intensity (70). Negative affect is also associated with an increase in attention towards pain stimuli, otherwise known as hypervigilance (71), which in turn can increase per- ceived pain intensity (72). In a recent study (73), hypervigilance for pain stimuli was examined in women with vestibulitis and matched control women. Results indicated that women with vulvar vestibulitis syndrome reported hypervigilance to coital pain and exhibited a selective attentional bias towards pain stimuli, an effect mediated by anxiety and fear of pain. These results suggest that anxiety and fear-mediated hypervigilance represent important factors for pain percep- tion in vulvar vestibulitis. Furthermore, hypervigilance to pain stimuli could exacerbate sexual impairment in women suffering from dyspareunia by distract- ing attentional resources away from erotic cues, a cognitive bias that has been associated with impaired sexual arousal (74 – 76). The role of sexual arousal in vulvar sensation has not yet been established; however, many theoretical models posit arousal as a key factor in preparing the female reproductive system for the “trauma” of coitus. Therefore, hypervigilance to pain stimuli in women with VVS may result in both a heightened awareness of pain and a dis- traction away from sexual stimuli, resulting in impaired sexual arousal which may further aggravate the pain experience.
Relationship factors: The examination of relationship factors has been quite limited despite the tremendous impact dyspareunia has on intimate relation- ships. Seventy-four percent of vestibulitis sufferers report that the pain impacts their relationships (77), although they do not typically report significant levels of dyadic distress. In addition, high dyadic adjustment is related to decreased pain severity in women with dyspareunia (78), whereas psychosocial attributions for the pain are associated with dyadic distress, suggesting an interaction between pain coping style and relationship adjustment (79). Further research is currently underway to clarify the complex relationship among pain severity, relationship adjustment, and coping styles in this population of women.
Wesselmann and colleagues (5,80) classify vulvodynia as a “dynia,” a group of well described but poorly understood chronic pain syndromes. Vulvodynia is defined as noncyclic, chronic vulvar discomfort extending to the urethral and rectal areas, characterized by the patient’s complaint of burning, stinging, irritation, or rawness (81). Light touch of the vulvar area often exacerbates the ongoing pain. A recent epidemiological study estimated that vulvodynia affects 6 – 7% of women in the general population, with a higher prevalence in women over the age of 30 (8). The onset of vulvodynia is usually acute, without a precipitating event. When such an event is recalled, it is often linked to episodes of local treatments, such as vulvar cream application or laser surgery (80). Little is known about the etiology of vulvodynia. McKay (82) proposed that the pain results from altered cutaneous perception, such as in neuropathic pain syndromes.