Objectives: To investigate the feasibility, safety, and efficacy of perineal cutaneous application of capsaicin as a test for the diagnosis, as well as a potential therapeutic tool, in patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).
Methods: We recruited 22 patients (mean age 34.5 years, range 19 to 56), who had been diagnosed with CP/CPPS according to the National Institutes of Health criteria, and 6 healthy control subjects. Both groups received a topical application of 5 mL capsaicin at a concentration of 10(-5) M to the perineal body skin. The patients were asked to mark on a visual analogue scale the intensity of any heat or burning sensation. All the patients had completed a National Institutes of Health Chronic Prostatitis Symptom Index before and 1 week after the test. The scores of the two groups were compared using the Mann-Whitney U test.
Results: The patients with CP/CPPS reported a heat/burning sensation intensity that was statistically greater than that of the healthy controls (7.5 versus 4.3, P <0.001) and a shorter time to heat sensation onset and maximal intensity (1.5 versus 3.4 minutes, P <0.001, and 2.5 versus 7 minutes, P <0.001, respectively). Of the 22 patients, 16 reported an improvement of symptoms after 7 days and the mean National Institutes of Health Chronic Prostatitis Symptom Index score decreased from 27 to 16 (P <0.01).
Conclusions: We found a statistically significant difference in the pain visual analogue scale and interval between topical application and the onset of the heat/burning sensation between patients with CP/CPPS and healthy controls. The small sample size strongly suggests the need for additional larger and more controlled studies.