title: Botulinum toxin A does not alter capsaicin-induced pain perception in human skin.
abstract: A genuine peripheral antinociceptive and anti-inflammatory effect of Botulinum neurotoxin type A (BoNT/A) has been proposed but could not be demonstrated in humans so far. Therefore, 100 mouse units of Botulinum toxin A (Dysport) and placebo were injected in a double blind paradigm in defined skin areas of 50 subjects. At baseline and after 4 and 8 weeks allodynia was induced in the skin areas with capsaicin ointment. Heat and cold pain threshold temperatures were measured with quantitative sensory testing, and threshold intensities upon electrical stimulation with a pain specific surface electrode were determined. No BoNT/A related differences in pain perception were found at any quality. There is neither a direct peripheral antinociceptive effect nor a significant effect against neurogenic inflammation of BoNT/A in humans.
authors.affiliation: Department of Neurology, University of Regensburg, Universitätsstr. 84, 93053 Regensburg, Germany. wilhelm.schulte-mattler@klinik.uni-regensburg.de
authors.forename: Wilhelm J
authors.initials: WJ
authors.lastname: Schulte-Mattler
authors.forename: Oliver
authors.initials: O
authors.lastname: Opatz
authors.forename: Wendelin
authors.initials: W
authors.lastname: Blersch
authors.forename: Arne
authors.initials: A
authors.lastname: May
authors.forename: Hans
authors.initials: H
authors.lastname: Bigalke
authors.forename: Kai
authors.initials: K
authors.lastname: Wohlfahrt
mesh_terms: D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D002211:Capsaicin / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009498:Neurotoxins / Q000008:administration & dosage; D009619:Nociceptors / Q000187:drug effects* / Q000502:physiology; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010919:Placebos; D011446:Prospective Studies; D011984:Sensory Receptor Cells / Q000187:drug effects* / Q000502:physiology; D012867:Skin / Q000187:drug effects* / Q000294:innervation
chemical_list: D018712:Analgesics, Non-Narcotic; D009498:Neurotoxins; D010919:Placebos; D019274:Botulinum Toxins, Type A; D002211:Capsaicin