For those suffering from a chronic, seemingly untreatable itch, there is no relief, just the never-ending need to scratch at their own irritant skin.
But now, scientists from Johns Hopkins Medicine say they have found a treatment that can actually satisfy such a ceaseless itch: cannabis.
Itching for cannabis
To reach their conclusions, the researchers examined the chronic pruritus (ongoing itch) of an African American woman in her 60s, who had been living with her skin condition for ten years. Scores of itchy spots lined her legs and torso.
After analyzing some skin samples, the Johns Hopkins scientists diagnosed the condition as Lichen amyloidosis, a kind of skin rash known to affect those in their 50s and 60s.
The blemish was undeterred by the researchers’ initial efforts, which included topical corticosteroids, phototherapy, topical capsaicin, and butorphanol nasal spray.
Once these standard methods proved fruitless, the Johns Hopkins team moved onto a more novel treatment. Twice a week, the patient was instructed to take medical cannabis, either by smoking flower (18 percent THC) or tinctures (CBD and THC at a 1:1 ratio).
“With the increased utilization of medical marijuana and our knowledge of the role of the endocannabinoid system in chronic itch, we decided to try medical marijuana with a patient who failed several therapies and had few options left,” Shawn Kwatra, an assistant professor of dermatology at the Johns Hopkins University School of Medicine, said in a statement.
Within ten minutes of cannabis consumption, the patient reported a significant decrease in her need to itch – from a 10/10 on the Worst Itch Numeric Rating Scale (WI-NRS) to 4/10. This difference was sustained over the course of a year and even improved to 0/10 WI-NRS during follow-up checks 16 and 20 months after the initial treatment.
“With continued use of the cannabis, the patient’s itch disappeared altogether,” Kwatra added.
Aside from some mild sedation, the patient reported no adverse effects, and was able to stop taking her other medications, including the corticosteroids, cholestyramine, and butorphanol spray.
While Kwatra and his colleagues can’t be sure why cannabis relieved the patient’s chronic itch, they believe the endocannabinoid system is involved. Cannabinoids are also known to antagonize the protein TRPV1, a known mediator of itch sensation. This action would result in reduced transmission of itch signaling.
Despite this promising effect, the Johns Hopkins team stress that further studies will be needed to properly assess the risk-benefit ratio of using medical cannabis for the relief of irritant skin.
“Controlled studies are needed to determine dosing, efficacy and safety for medical marijuana in the treatment of various human itch subtypes, and once those are performed, we will better understand which patients are most likely to benefit from this therapy,” Kwatra said.