title: High concentration capsaicin for treatment of peripheral neuropathic pain: effect on somatosensory symptoms and identification of treatment responders.
abstract: BACKGROUND
  Pain is usually assessed by spontaneous pain ratings. Time-dependent (brief attacks) or evoked (allodynia) phenomena, common in neuropathic pain, are not captured. To evaluate the overall effectiveness of a treatment, improvement of all sensory symptoms should be measured. Since the pattern of sensory abnormalities might hint at the underlying mechanisms of pain, this baseline information may aid in predicting the treatment effect. Data on sensory neuropathic abnormalities (painDETECT questionnaire) were analyzed aiming to (1) evaluate the frequency of neuropathic symptoms in different peripheral neuropathic pain syndromes, (2) assess the effect of capsaicin 8% patch on neuropathic symptoms and (3) identify treatment responders based on baseline values.
  
  
  METHODS
  Data analysis of a prospective 12 week non-interventional trial in peripheral neuropathic pain treated with capsaicin 8% cutaneous patch. Average pain intensity during the past 24 hours, pain descriptors and qualities of neuropathic pain were assessed to characterize the patients' sensory symptoms at baseline and to document changes.
  
  
  RESULTS
  (1) Characteristic symptoms of neuropathic pain were present in all peripheral neuropathic pain syndromes, but frequencies varied in the individual syndromes. (2) Topical capsaicin 8% treatment significantly reduced the overall pain intensity and resulted in a reduction of sensory abnormalities. (3) Short disease duration predicted a better treatment effect. High painDETECT scores, the presence of burning and pressure-evoked pain were weakly associated with treatment response.
  
  
  CONCLUSIONS
  Topical capsaicin 8% treatment effectively reduced sensory abnormalities in peripheral neuropathic pain. The association of sensory symptoms and treatment response aids in understanding the mechanism of action of high concentration capsaicin. It is, however, not possible to use sensory symptom patterns to predict treatment response to capsaicin on an individual level.
  
  
  CONCLUSIONS
  Completion of painDETECT was optional and therefore data was not available for all patients. Further studies for confirmation of these results are needed.
authors.affiliation: Division of Neurological Pain Research and Therapy, Department of Neurology, University Hospital Schleswig-Holstein , Kiel , Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Höper
authors.forename: Stephanie
authors.initials: S
authors.lastname: Helfert
authors.forename: Marie-Luise S
authors.initials: ML
authors.lastname: Heskamp
authors.forename: Christian G
authors.initials: CG
authors.lastname: Maihöfner
authors.forename: Ralf
authors.initials: R
authors.lastname: Baron
mesh_terms: D000328:Adult; D000368:Aged; D002211:Capsaicin / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000188:drug therapy*; D011446:Prospective Studies; D018689:Sensory System Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D020886:Somatosensory Disorders / Q000188:drug therapy*; D011795:Surveys and Questionnaires
chemical_list: D018689:Sensory System Agents; D002211:Capsaicin