Study Evaluating the Analgesic Efficacy of Capsaicin 8% Patches in Chronic Coccygodynia.

Inclusion Criteria: * \>18 years old at the pre-inclusion visit * Presenting with chronic coccygodynia: pain in the coccygeal region, increased by sitting and or when rising from a sitting position and pain over the last ten days of intensity greater than or equal to four on the eleven-point numerical scale (from zero to ten) and having been present for more than 3 months. * Failure of previous treatments: NSAIDs, pressure-relieving cushions and/or infiltration or having a contraindication to these treatments, or not wishing to receive these treatments * Have never been treated with an 8% capsaicin patch for this indication * With at least one clinical sign suggestive of neuropathic pain (burning, painful cold, numbness, tingling, electric discharge, allodynia of the gluteal groove, allodynia to pressure on the coccyx) * Proficiency in reading and writing the French language * Be affiliated to the social security system * Have signed an informed consent form * Women must meet one of the following criteria at the time of inclusion: * be using adequate contraceptive measures, and have a negative pregnancy test (specify if urine or blood test) prior to receiving the first dose of trial medication; * or be post-menopausal (aged over 50 with amenorrhoea for at least 12 months after stopping all exogenous hormonal treatments) * or (if under 50) have been in amenorrhoea for at least 12 months after stopping all exogenous hormone treatments and with luteinising hormone (LH) and foll…