Year: 2018
Type: article
Abstract: Vulvodynia is defined as an inability to experience pain-free vaginal penetration. It is a clinical diagnosis based on the exclusion of causative dermatological, infectious or endocrine factors. In the absence of objective laboratory criteria it is inevitable that multiple aetiologies will be present in women with this diagnosis. It has been proposed that vulvodynia may be due to excessive local inflammation, sensitivity to a prior or current infection or dietary components, elevated local nerve fibre proliferation, hormonal alterations, central pain anomalies, pelvic floor muscle dysfunction, genetic factors or past psychological trauma (Lev-Sagie & Witkin. F1000Res 2016;5:2581; Falsetta et al. BJOG 2017;124:210–8). It is likely that each of these proposed aetiologies is relevant in a particular subset of women. In the accompanying paper, Pereira and co-investigators (BJOG 2018;125:1216–24) report their findings from a systematic review of drug treatments for vulvodynia. They conclude that most studies were under-powered, preventing acquisition of unambiguous results. Furthermore, women in the placebo control groups often benefitted to the same extent, or did even better, than those women receiving the medical intervention. A 2006 paper asked the question: 'Are you a lumper or a splitter?' (Ledger & Witkin. Am J Obstet Gynecol 2006;195:1205–9). Clearly, if women with a similar clinical diagnosis are all lumped together into a single group for a treatment trial, the outcome will be equivocal due to patient heterogeneity. To obtain reliable results, subjects must be split into clearly defined groups based on probable aetiology before initiating a treatment trial. This appears to be especially relevant in vulvodynia research. A particular treatment may be effective in relieving the symptoms of vulvodynia in a subset of patients. However, this outcome will be masked by the ineffectiveness of the treatment in those with a different underlying cause and the overall findings will show no significant clinical benefit in the population being evaluated. Clearly, drug treatment trials on groups with multiple underlying causes for the same clinical entity are bound to fail. There is an urgent unmet need to identify criteria that will effectively separate women with vulvodynia into discrete groups based on aetiology. There are claims that vulvodynia is successfully alleviated by a variety of interventions: hypnosis, types of psychotherapy, acupuncture, pelvic floor muscle relaxation treatments, dietary changes, certain drug regimens and surgical excision of regions of the vaginal vestibule. A striking observation in the Falsetta study (Falsetta et al. BJOG 2017;124:210–8) is that many women obtained symptomatic relief, i.e. experienced less painful vaginal penetration, if they believed their treatment (a placebo) would be effective. This highlights the existence of a psychological component in many cases of vulvodynia. In addition, the likelihood that almost any intervention may succeed in a subset of patients (placebo effect) should make women with vulvodynia and their caregivers wary of claims of curative treatments based on inadequately designed and poorly controlled interventions. The discovery of effective long-term treatments for vulvodynia awaits development of tests that divide women into discrete categories based on presumed aetiology, followed by the performance of sufficiently large randomised, double-blind, placebo-controlled trials. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Author: SS Witkin
Institution: Weill Cornell Medicine
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2795202163