Vulvodynia used to be called vulvar vestibulitis syndrome, or VVS. Vulvodynia is a chronic pain disorder, lasting at least 3–6 months, localized to the region at the opening of the vagina, the vulvar and vestibule regions. For many women the pain simply hurts “down there”. Vulvodynia is not a single condition, rather vulvodynia is a constellation of different conditions with various clinical presentations. Various studies have shown that vulvodynia affects approximately 15% to 20% of adult women. It is the most common cause of sexual pain in premenopausal women and one of the most difficult for most doctors to correctly diagnose and treat.
Strictly speaking, however, there are important embryologic differences among tissues of the vulva, the vestibule and the vagina. The vulva is embryologically derived from skin (genital ridges or folds). The vagina is derived from Müllerian tissue. The vestibule is derived from urethral/bladder tissue (the primitive urogenital sinus). The vulva consists of the labia majora, the mons pubis, the pubic hair, the outside surface of the labia minora, and the clitoris and clitoral hood. Many skin and infectious diseases adversely affect the vulva.
On the other hand, the vestibule surrounds the opening of the vagina and is approximately 1/2 inch wide starting at the hymenal remnant of the vaginal opining and extending to approximately half way along the inner surface of the inner lips called the labia minora. The inner and outer surface of the inner lips, the labia minora, are separated by Hart’s line. At Hart’s line, the outermost surface of skin, called the stratum corneum, stops. As a result, the vestibule has a whitish color (no stratum corneum) while the vulva, containing the stratum corneum is brown or black as it is the color and thickness of regular skin. The vestibule contains mucous-secreting or pre-cum glands that release lubrication during sexual arousal. These glands, called minor vestibular glands, surround the opening to the vagina. There are also two major vestibular glands, called Bartholin’s glands. They also secrete mucous during sexual arousal. There are several disorders that adversely affect ONLY the vestibule and do not adversely affect the vulva.
Strictly speaking, therefore, the term vestibulodynia should be used when the sexual pain disorder is exclusively related to the anatomic/embryologic confines of the vestibule.
Patients with provoked vulvodynia or vestibulodynia may experience severe burning, cutting, or searing, raw-like pain at the opening to the vagina upon some sort of provocation such as Q-tip (cotton swab) testing or upon initial vaginal penetration. Generalized vulvodynia or vestibulodynia is used if the pain exists all the time and is not related to provocation.
Vulvodynia or vestibulodynia may be the result of many different causes. These may include inflammatory and infectious disease processes, neurologic conditions, genetic factors, stress factors, and hormone factors. As a result, one management strategy for all women with complaints of vulvar pain will likely not be successful.
When specifically addressing provoked vestibulodyna (PVD), the most common causes are hormonal changes, tight (hypertonic) pelvic floor muscles, and an increased number of nerve endings in the mucosa of the vestibule.
More research is needed to better understand the basis for disease in the vestibule that avoids the tissues of the vulva and the vagina. One theory is that vestibular tissue, in particular, tissue from the vestibular glands, has hormone receptors for testosterone and estradiol. In some women, the provoked vestibulodynia may be caused by a hormonal- mediated vestibulodynia where there is an absence of these hormone receptors. A common risk factor for hormonal-mediated provoked vestibulodynia is use of hormonal contraception, the birth control pill, the patch or the ring. In such cases, the preferred treatment is to discuss with the healthcare provider stopping the hormonal contraception and to consider other options. In addition, hormonal treatment is started with either local estradiol to the vestibule and systemic testosterone, or local estradiol and local testosterone in a hypoallergenic cream.
Other research to understand the basis for disease in the vestibule that avoids the tissues of the vulva and the vagina is based on a non-hormonal theory. Multiple investigations have observed a proliferation or growth of pain nerves, called “c-afferent nociceptors” in the skin layer of the vestibule. In some patients with provoked vestibulodynia, there has been found to exist a 10-fold increase in the density of pain fiber nerve endings in the vestibule skin lining compared to women who did not have provoked vestibulodynia. This high density of nerve endings, called neuronal hyperplasia, may explain the fact that women with provoked vestibulodynia experience severe pain or burning or rawness from a stimulis (Q-tip) that does not normally cause pain. The medical word for pain from a stimulus that does not normally lead to the sensation of pain is allodynia and allodynia exclusively in the vestibule is the classic finding in women with provoked vestibulodynia.
For women with primary or lifetime provoked vestibulodynia, it is felt by some experts that the high density of pain nerves in the vestibule has occurred as the result of a congenital accumulation of nerve fibers, called congenital neuronal hyperplasia, in the tissue derived from the urethral/bladder region or the primitive urogenital sinus.
For women with secondary or acquired provoked vestibulodynia, researchers have shown the high density of pain nerves in the vestibule has occurred as the result of healing cells called mast cells excessively releasing a protein called nerve growth factor. The mast cells may be responding to a healing stimulus from an allergy on the skin of the vestibule from medications used for yeast infections, or from trauma to the vestibule from bicycle riding or spinning, or from local treatments from diseases such as herpes or HPV. Once the nerves have proliferated, they are not known to disappear.
Additional factors are theorized to play a role in why there is thought to be acquired provoked vestibulodynia. It is now observed that some women with acquired secondary provoked vestibulodynia have the existence of different DNA sequences in genes that express important enzymes. The role of these enzymes is to terminate the body’s response to inflammation in the vestibule. In some women with secondary provoked vestibulodynia, their genetic polymorphisms in important healing genes, results in an in- grown tendency to have continued inflammation and continued release by the mast cell of the protein nerve growth factor in the vestibule. Once the pain nerves have proliferated in the vestibular tissues, they are not known to disappear. If appropriate conservative treatments for relief of pain have been tried but are not successful, then vestibulectomy surgery is considered.
There are multiple other causes of provoked vulvodynia or provoked vestibulodynia including dermatologic conditions such as lichen sclerosus, and lichen planus, infectious reasons such as chronic infection from candida, tissue injury reasons from a fissure that forms in the posterior fourchette often related to poorly healing episiotomy repairs post-partum. There is an non-infectious, likely allergic condition called desquamative inflammatory vaginitis associated with an intense inflammation of the vaginal lining of unknown etiology.
One should avoid chemicals or medications that can be irritating to the vulva such as scented menstrual pads, soaps with perfumes, and other the counter yeast creams. Additionally, if a woman experiences decreased libido and/or lubrication after starting hormonal contraceptives, she should be aware that hormonal contraceptives may lead to provoked vestibulodynia.
Associated with varying pain intensities and triggers, vulvodynia or vestibulodynia pain may be unremitting, intermittent or episodic; more intense at a certain time in the menstrual cycle or occurring only with touch (provoked). Symptoms of vulvar vestibular burning and itching may also vary. Pain in the vulvar, vestibular region causes bother and concern and can have significant negative consequences on interpersonal and psychological wellbeing. On physical examination of the pelvic floor, women with vulvodynia or vestibulodynia have increased spasm and increased tone of the levator ani muscle in response to vulvar pain.
There are certain disorders that adversely affect only the vestibule. This can only truly be established during a careful physical examination.
In vestibulodynia patients when compared to women without vestibulodynia, studies have shown vestibular tissues to have more redness (erythema). Biopsies of the vestibule have shown more areas of chronic inflammation and more pain nerve fibers in vestibulodynia patients as well compared to women without vestibulodynia
Women who have had pain in the vestibule and not the vagina or vulva ever since their first attempt at intercourse or tampon insertion or first finger insertion or first gynecologic examination have what is considered to be primary provoked vestibulodynia (PVD). Women who have had an initial interval of pain free sexual intercourse prior to the onset of bothersome pain symptoms exclusively at the vestibule are considered to have secondary vestibulodynia. The purpose of sub-classifying provoked vestibulodynia is for clarity of treatment. Those with primary provoked vestibulodynia have an excellent successful outcome at vestibulectomy surgery and may avoid many of the conservative therapies used for women with sexual pain. Women with secondary provoked vestibulodynia may consider surgery but only as a last resort having tried and often found success with non-surgical treatment options.
Q-tip or cotton swab testing of the vestibule, vulva and distal or outer vagina helpsestablish the localization of the pain and is used to identify the allodynia, the unusual reaction to sensation testing that otherwise should not be interpreted as painful or burning or raw. Vulvoscopic investigation with magnification and photography is important to carefully inspect the vulva, vestibule and vagina and to identify regions of redness or erythema and that these regions are localized to the vestibule. Pelvic floor assessment of the tone of the superficial, intermediate and deep pelvic floor muscles is performed. Perineometry is a test that measures objectively the tone of the pelvic floor muscles at baseline, during thrusting and during a voluntary “Kegel” contraction. A vaginal smear and wet mount and vaginal culture helps identify infectious etiologies. Hormonally- mediated provoked vestibulodynia requires a thorough and detailed hormonal evaluation. Dermatologic conditions associated with provoked vestibulodynia require a tissue biopsy and pathologic examination.
A diagnostic marcaine-epinephrine nerve block of the vestibule can be performed in individuals who are suspected as having neuro-proliferastive vestibulodynia, have failed conservative therapies, and do not have any infections or dermatologic causes of provoked vestibulodynia. Should administration of marcaine 0.25% with 1:200,000 epinephrine result in absence of pain to cotton swab testing and digital palpation at the introitus, it has been our experience that in this setting the diagnosis is likely neuro- proliferative vestibulodynia, and that complete vestibulectomy has a high rate of success. Physical examination including cotton swab testing of the vestibule is performed prior to the nerve block. The minor vulvar vestibular glands at 1:00, 5:00, 7:00, 9:00 and 11:00 are examined for erythema and for allodynia discomfort to cotton swab testing. Poviodne-iodine is then applied to the introitus. A total of 20 ml marcaine 0.25% with 1:200,000 epinephrine is administered submucosally around the introitus. Ten minutes following the nerve block, cotton swab testing of the vestibule is re-assessed. Digital palpation around the vestibule is performed. The patient is allowed to go home and assess the degree of discomfort and pain symptoms. Patients who achieve a great relief of symptoms have a positvie is diagnostic nerve block test. This is considered consistent with the existence of local vestibular pathology such as high density of pain nerve fibers in the vestibule – neuro proliferative vestibulodynia. A positive test is in our experience consistent with high success following complete vestibulectomy surgery.
The diagnosis of provoked vestibulodynia is made with a simple procedure know as a Q- tip test. The vulvar vestibule is gently touched with a cotton swab to see if it is painful. Additional tests include examination of the vaginal discharge (wet mount and culture) evaluation of the muscles of the pelvic floor, a visual examination of the vulva with a microscope (vulvoscopy), and hormonal testing.
Unfortunately, despite vulvodynia or vestibulodynia being relatively common and often associated with high distress, there are minimal evidence-based data to guide health care professionals in the management of women with vulvodynia.
If the cause of the chronic vulvar or vestibular pain is known, medical attention can then be directed to the underlying cause. Some examples of known causes of vulvar pain include: vulvovaginal Candida or yeast infections, endometriosis of the vulva, lichen sclerosis or lichen plannus of the vulva, contact dermatitis of the vulva, atrophy of the vulva from low levels of sex steroid hormones, pudendal nerve entrapment syndrome, referred pain from tender pelvic floor muscles, post-operative painful vulva after perineal surgery, painful vulva following pelvic or perineal radiation therapy for cancer, and other pain syndromes including referred pain misdiagnosed as coming from the vulva. Pain in the perineum can actually come from the urethra such as from urethritis, from the bladder such as from interstitial cystitis or even from the coccyx area. Risk factors for the development of vulvar pain include irritable bowel syndrome, interstitial cystitis, and oral contraceptive pills.
One of the most distressing aspects of vulvodynia or vestibulodynia is that afflicted women frequently experience pain for many months, often years, before being diagnosed. Many women with chronic vulvar pain are told that their symptoms are “all in their head,” implying that their pain is not real. Lack of a diagnosis may further increase the distress caused by the vulvodynia and delay access to more specialized medical care often needed for this condition.
When the cause of chronic vulvar pain is not known or is at best uncertain, treatment interventions vary. Many health care professionals combine treatments including psychotherapy and/or behavioral counseling, pain medication, pelvic floor physical therapy, hormone treatments if indicated, and, as a last treatment option, surgical removal of portions of the affected vestibule. More research is needed to better understand how to manage vulvodynia. Topical anesthetic such as lidocaine and antidepressants such as amitriptyline can be used to numb the tissue of the vulva or vestibule. If the cause is hormonal then treatment with topical estrogen and possibly testosterone is may be considered. If the muscles are tight then pelvic floor physical therapy, muscle relaxants, biofeedback, and Botox injections may be used. If there is an increased number of nerves then topical anesthetics, anti-epileptics, anti-depressants, and capsaicin can be used to numb the nerves.
If appropriate conservative treatments for relief of pain have been tried but are not successful, then vestibulectomy surgery is considered to remove the nerves. As part of surgical treatment, patients will undergo prolotherapy (dextrose injections) and shockwave therapy to decrease pain and reduce opioid need post-operatively.
When discussing vestibulectomy surgery, it is critical that the surgery involves contemporary strategies. First, that contemporary vestibulectomy involves removal of ALL of the vestibule tissues and not a focal area of the vestibule such as the floor of the vestibule. Focal surgeries, such as a posterior vestibulectomy do not take into account the current theory of neuronal hyperplasia, either congenitally-based or trauma/ inflammation-based, that extends to all the regions of the vestibule. Second, in addition to removal of all of the vestibular tissue, there needs to be a vaginal advancement flap developed that covers the removed vestibular tissue at the floor. Third, to prevent the vaginal advancement flap from being torn during recovery, there need to be two layers of so-called anchoring sutures that pass from the advancement flap to the surrounding tissues between the vagina and the rectum. Fourth, to prevent narrowing of the vaginal opening, the anchoring sutures need to be passed in a horizontal plane such that when the anchoring suture is tied, the vagina advances and does not narrow. Adhering to these contemporary strategies during vestibulectomy surgery allows for a high success rate with minimal side effects or complications.
Thus, in women with primary provoked vestibulodynia, removal of the congenital neuronal hyperplasia in the vestibule is the key to the first phase of recovery post- vestibulectomy surgery. Similarly in women with secondary provoked vestibulodynia, removal of the mast cell induced neuronal hyperplasia in the vestibule is the key to the first phase of recovery post-vestibulectomy surgery.
The second phase of recovery involves an extensive rehabilitation with a pelvic floor physical therapist specialist who treats high tone pelvic floor dysfunction. Since the biologic basis is removed surgically, then the muscles will eventually relax following pelvic floor therapy and the woman with sexual pain can be effectively and successfully cured. An important principle is that pain in the vestibule, at the opening of the vagina, causes the muscles in the pelvic floor to have high muscle tone and often go into muscle spasm. Pelvic floor physical therapy is a critical part of the overall care and management of women with provoked vestibulodynia. However, the other side of this is that there can be no obvious biologic reason for high tone pelvic floor muscle dysfunction. The relaxation provided by pelvic floor physical therapy will return to high tone if there is a biologic reason for pain and thus muscle contractions.