Dr. Shawn Kwatra discusses the science behind using medical marijuana for itch as well as other possible dermatologic indications.
Shawn Kwatra, MD, is Assistant Professor of Dermatology at Johns Hopkins Medicine, Baltimore, Md.
“Medical marijuana and its efficacy is based on the role of the endocannabinoid system… and there have been studies that have shown that the endocannabinoid system plays an important role in skin homeostasis in addition to broader effects on neurogenic responses,” said Shawn Kwatra, MD, in an exclusive interview with The Dermatology Digest.
Dr. Kwatra, MD, a dermatologist and faculty member at Johns Hopkins Medicine, Baltimore, MD, recently reported a case in which he and colleagues successfully treated itch with medical marijuana.1 This treatment choice was based on the role and known interactions of cannabinoids derived from the cannabis plant and the endocannabinoid molecules in the body.
The role of cannabinoids in pain is thought to be similar to that of the potential role in pruritus, according to Dr. Kwatra, who notes they increase activity of the two G protein-coupled receptors, cannabinoid (CB)1 and CB2.
Overall, said Dr. Kwatra, the decision to use medical marijuana to treat itch was based on neuroimmune modulation: Itch involves A-delta and C nerve fibers, which transmit pain. The transmission pathway (central and peripheral) and agonism also appear to reduce pruritus and immune cell mediators.
“[All of this] really provided a lot of evidence for for trying it—actually much more evidence than we have for things that we use like antihistamines,” he said
When asked about other possible dermatologic indications for medical marijuana, Dr. Kwatra mentioned hidradenitis suppurativa and pyoderma gangrenosum, noting that it may offer needed relief to patients with other skin conditions in which itch or pain affect daily life.
He also cautions that more research is needed to definitively determine treatment conditions and dosing. However, “…our patients can’t wait sometimes and so it’s always nice to have something else in the toolbox, you can turn to when you have a difficult time managing a patient.”
Reference
1. Roh YS, Sutaria N, Biles NF, Kwatra SG. Treatment of Chronic Pruritus With Medical Marijuana. JAMA Dermatol. Published online April 09, 2021. doi:10.1001/jamadermatol.2021.1194