VULVAR PAIN SYNDROMES A bounty of treatments—but not all of them are proven
Treatments for vulvodynia and vestibulodynia range from lifestyle adjustments and application of topical agents to tricyclic antidepressants and nerve blocks—but the data on their efficacy are not as bountiful
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Dr. Haefner: Capsaicin activates A-delta sensory neurons and unmyelinated C fibers. It is a vanillyl amide that evokes the sensation of burning pain. It has been proposed as a means of desensitization, which occurs as an acute reaction mediated by neuropeptides (including substance P).17 Steinberg and colleagues found that topical capsaicin significantly decreased pain with intercourse.17 Patients applied capsaicin 0.025% cream for 20 minutes daily for 12 weeks.
In a study by Murina and colleagues, 33 women were treated with topical capsaicin 0.05%. The capsaicin cream was applied to the vulva twice daily for 30 days, then once daily for 30 days, then twice weekly for 4 months. In this study, however, the response to treatment was only partial.18
Dr. Edwards: I have never had a patient willing to try capsaicin after I describe the therapy to them.
Dr. Gunter: Two studies have evaluated daily applications of capsaicin in concentrations of 0.025% and 0.05%—one of them the study by Murina and colleagues that Dr. Haefner mentioned.2,18 The initial release of substance P causes significant burning on application, so pretreatment with local anesthetic to help the patient tolerate the capsaicin is recommended, which could potentially confound the results. In one study, daily pain scores, as well as pain with intercourse, improved significantly for 59% of participants, but no patient experienced complete resolution of symptoms—and within 2 weeks after capsaicin was discontinued, symptoms returned.2,18 I have had only one patient in 15 years of practice who was willing to try capsaicin and who could get past the initial burning.
Another application for botulinum toxin type A?
Dr. Lonky: Is botulinum toxin type A [Botox] at all effective?
Dr. Haefner: Botulinum toxin type A has been utilized to treat provoked vestibulodynia as well as vaginismus and was beneficial.19-23 It blocks the cholinergic innervation of the target tissue. The therapeutic dose ranges from 20 IU to 300 IU.24
A placebo-controlled trial found that injection of 20 IU of botulinum toxin into the vestibule of women with vestibulodynia did not reduce pain, improve sexual functioning, or impact the quality of life, compared with placebo.25 However, this study utilized a lower dose of botulinum toxin than was used in many of the other studies.
Dr. Edwards: I have only used botulinum toxin type A in a low dose. I injected 6 IU of botulinum toxin A into the periphery of the vestibule at 3, 6, 9, and 12 o’clock in six patients, and half improved modestly. I am not prepared to use electromyography (EMG) localization in my office, but from anecdotal reports, as well as several small series and placebo-controlled trials, I would conclude that some patients improve. Those who have hypertonic pelvic floor muscles are likely to be the best candidates for this treatment.
Because the agent relieves pain only modestly, and because it is not covered by insurance for this application, I refer the patient to a gynecologist in my area who administers the drug under EMG localization.
Dr. Gunter: Given the well-documented effect on muscle spasticity, as well as studies that suggest they are also anti-nociceptive agents, botulinum toxins are certainly an attractive concept for vulvodynia. A small case series and a case report indicated significant improvement with vestibular injections of 20 to 40 U of botulinum toxin. However, a randomized, placebo-controlled, double-blind study indicated no significant improvement for women with localized vestibular pain.25-27
I discuss botulinum toxin A with my patients. I explain that my clinical experience does differ from results published in the literature. I find that many women with vestibulodynia opt to try an injection before proceeding to vestibulectomy.
When combined with pelvic floor physical therapy, botulinum toxins are highly effective at treating muscle spasm and can be very useful for women who have a component to their pain of vaginismus or high-tone pelvic floor dysfunction.
How useful are steroids and nerve blocks?
Dr. Lonky: Is there a role for local injections of glucocorticoids or serial nerve blocks?
Dr. Edwards: The occasional patient with very localized pain (trigger point) responds fairly well in my office to intralesional corticosteroids. I have not used or seen reports describing administration of intralesional corticosteroids into a larger area, although two practitioners have told me informally that it is useful in their hands.
As a dermatologist, I cannot perform blocks. I have referred patients to gyn and pain clinics for this purpose, but neither venue has been willing to administer the blocks.
Dr. Haefner: Patients who present with small, localized areas of pain may benefit from local injections. In small areas—for example, a painful spot 1 cm in diameter—triamcinolone acetonide in combination with bupivacaine may be helpful. It is important to use a small dose of steroid in a small area, however, because tissue erosion or ulceration can occur with too high a dose of steroid in the skin. For large areas, as much as 40 mg of triamcinolone acetonide may be utilized in a single monthly dose. Generally, the dose is repeated monthly, if necessary, as many as three or four times.
