“Cannabinoids have been used for their analgesic and euphoric effects for millennia, but recently the antipruritic effects of cannabis have been discovered.
Considering the similarities between pain and itch sensations, we hypothesized that cannabinoid receptors may play a role in the antipruritic effects of cannabinoids.
Our findings support prior researches indicating that cannabinoids exert antipruritic effects. Moreover, our results show that the antipruritic effects of cannabinoids are partially mediated by spinal CB1 receptors.”
https://www.ncbi.nlm.nih.gov/pubmed/29424035
http://onlinelibrary.wiley.com/doi/10.1111/ced.13398/abstract