Diagnosis and Management of Generalized Vulvodynia
Vulvodynia is defined as chronic vulvar itching, burning, and/or pain that causes physical, sexual, and psychological distress. Over the years, the term has been applied to a wide variety of vulvar conditions because specific diagnostic criteria were not established. Although the prevalence of chronic vulvar pain in the U.S. is unknown, for the past decade estimates have ranged from the low to mid-hundred thousands. While it was previously thought that chronic vulvar pain is a rare complaint, it may simply have been under-recognized by the medical profession — in fact, the disorder only received a diagnostic code about five years ago. Last fall, the National Institute of Child Health and Human Development funded a 5-year prevalence study on vulvodynia in the general population. According to epidemiologist Bernard Harlow, PhD, associate professor of Obstetrics, Gynecology, and Reproductive Epidemiology, Harvard Medical School, “the preliminary data suggests that possibly millions of women may be affected at some point during their lifetime.”
After a 1997 workshop at the National Institutes of Health, practitioners began to conceptualize vulvodynia as a pain problem. In 1999, at the annual meeting of the International Society for the Study of Vulvovaginal Disease, a two-year trial of specific pain terminology was proposed. This new terminology includes generalized vulvar dysesthesia (VDY), formerly known as dysesthetic or essential vulvodynia, burning vulva syndrome, pudendal neuralgia, or perineal pain syndrome. It is characterized by pain that may be located anywhere on the vulva. Localized vulvar dysesthesia refers to pain that can be consistently localized by point-pressure mapping within specific areas of the vulva, and mixed dysesthesia describes pain on touch in the vulvar vestibule as well as pain in other areas of the vulva.
VDY can take the form of burning or any combination of stinging, irritation, itching, pain, or rawness anywhere from the mons pubis (bony protrusion where the pubic hairline begins) to the anus. It may be diffuse or focal, unilateral or bilateral, constant or sporadic. Women with VDY frequently have difficulty describing and localizing their pain. Many feel that they have a constant yeast infection. Others mention constant irritation, a feeling of continual swelling, a raw sensation, or the sense that they are sitting on a hard knot or ball. Brief paresthesias (abnormal sensations such as burning, prickling or tingling) also are characteristic. Involvement of the urethral meatus (opening of the urethra) leads to symptoms resembling those of a urinary tract infection — i.e. , frequency, urgency, and dysuria — with negative urine cultures.
Dyspareunia (painful intercourse) may or may not be a feature of VDY, although intercourse may trigger pain. Tight pants or undergarments or even the movement of pubic hair also may provoke discomfort. At the same time, it is not unusual for women to report symptom-free periods lasting days or weeks.
The pain of VDY may be neuropathic in nature. Neuropathic pain states originate with an injury to the sensory nervous system itself, which continues to transmit pain signals even when acute injury is absent. Neuropathic pain is most commonly a result of peripheral neuropathy, nerve or root compressions, trauma, or other injuries to the peripheral nervous system. Any surgical incision damages sensory nerves and can cause chronic neuropathic pain, even when the original neural injury is insignificant or unapparent.
As it crosses the sacrospinous ligament and courses along the pelvic sidewall, the pudendal nerve is vulnerable to traction (pulling), pressure, and injury from a wide variety of insults. Injuries from unicycles or horseback riding are documented examples of sports trauma leading to vulvar pain. Injury from descent of the presenting part of the fetus during delivery, recognized in the pathophysiology of prolapse and incontinence, also is a possible etiology of VDY. Some types of vaginal surgery may injure the pudendal nerve, resulting in VDY.
The pinformis, pubococcygeus, and obturator internus and externus muscles (pelvic floor muscles) as well as the sacroiliac joint, commonly refer pain to the perineum, vagina, and rectal areas. Branches of the pudendal nerve lie directly over the belly of the obturator internus muscle. Any injury or orthopedic condition affecting these muscles and joints — e.g. injury to the back, hips, or knees, or repetitive musculoskeletal or postural stressors — can result in vulvar pain.
Pain also may be referred to the vulva from a ruptured disc or scarring around sacral nerve roots after disc surgery, spinal stenosis, or significant spinal arthritis. In addition, neurologic disease such as multiple sclerosis may lead to vulvar pain, as may a solitary neurofibroma (benign nerve tumor).
The neuropathic viruses varicella zoster and herpes simplex may lead to post-herpetic neuralgia manifesting as VDY. When a lesion thought to be herpes simplex turns out to be culture-negative, herpes zoster may be present. VDY should be considered when a woman with a history of herpes is successfully suppressed on acyclovir but continues to complain of irritative symptoms or pain.
Since irritation, burning, and sometimes an increase in discharge are features of VDY, many women believe they have yeast or other vaginitis symptoms. Patients often are treated for bacterial and/or yeast infections, but multiple antifungals and antibiotics fail to resolve irritative symptoms. Women whose VDY mimics a urinary tract infection will have negative urine cultures, fail to respond to antibiotics, and have a negative urologic workup. Many women are sent to dermatologists to determine whether there is a skin etiology for the chronic symptoms, especially since VDY sometimes involves fissuring with sexual activity. Topical steroids usually are of no benefit. In the postpartum and menopausal periods, estrogen cream may be soothing for a short time but will not dispel discomfort or dyspareunia.
The diagnosis of VDY is largely a diagnosis of exclusion. A careful history is essential to ascertain the type of pain as well as it’s behavior and location.
The diagnosis of VDY is largely a diagnosis of exclusion. A careful history is essential to ascertain the type of pain as well as it’s behavior and location. The clinician should inquire about any initiating factors or associated events such as medical illness, pelvic or vulvovaginal surgery, childbirth, injury to the back or hips, or development of a vulvar lesion that may provide clues to etiology. Any history of sports injury, back surgery, herniated disc, arthritis, spinal stenosis, and hip dislocation also is important. In addition, the clinician should ask about occupational and leisure-time activities that might affect the back or pelvis.
During the physical, it is important to look for skin or oral lesions suggestive of disease or dermatosis. Labial and anal muscle reflexes should be tested, and the patient should be asked to point out areas of pain and identify areas tender to the touch.