Use of High-Concentration Capsaicin Patch for the Treatment of Pelvic Pain: Observational Study of 60 Inpatients.

BACKGROUND Chronic pelvic, perineal and gluteal neuralgia is often experienced in a similar way to neuropathic pain, in the territories of four nerves: ilio-inguinal, pudendal, inferior cluneal and posterior gluteal nerves. These pains are often refractory to medical treatment based on the use of systemic molecules with disabling adverse effects and surgical procedure may be necessary. OBJECTIVE The objective of this study was to evaluate the efficacy and safety of treatment with a high-concentration capsaicin patch in these indications. STUDY DESIGN This study was prospective, nonrandomized, and observational. SETTING Federative Center of Pelvi-Perineology in the University Hospital of Nantes, France. METHODS Sixty patients with pelvic neuralgia were treated with high-concentration capsaicin patch. The primary endpoint was Patient Global Impression of Change (PGIC) and secondary endpoints included pain intensity on a Numerical Rating Scale (NRS), maximum sitting duration at the end of the day, Medication Consumption Score (MQS), and patient global improvement (from -100% to + 100%). RESULTS Twenty four percent of the 60 patients included in the study declared that they felt "very much improved" or "much improved" (PGIC = 1 or 2) and these patients reported an average 58% improvement and a 3.4-point reduction on the NRS. Among the "good responder" patients, patients with coccygodynia appear to obtain the bestresults, as 37% of these patients declared that they were much improved with an average 63% improvement No serious adverse effects were observed and treatment was well tolerated. LIMITATION This study is limited by its relatively small sample size and non-randomized study. CONCLUSION These results suggest the value of high-concentration capsaicin 8% patch in the treatment strategy for patients with chronic pelvic, perineal and gluteal neuralgia. This treatment would be particularly indicated in the management of coccygodynia.Key words: Pelvic pain, neuropathic pain, pudendal nerve, ilio-inguinal nerve, inferior cluneal nerve, posterior gluteal nerve, capsaicin, capsaicin patch, coccygodynia.