Pruritus is a medical/show-off way of saying “itchy.” Obviously, it has many causes, such as dry skin, allergies, or woolen undergarments. But itching is also a symptom of much more serious conditions, including liver disease and kidney failure. It’s also one of the common miseries that accompany chemotherapy.
While pruritus is not life threatening, anyone who’s suffered through, say, a case of chickenpox or poison oak knows that chronic itching is a genuine torment. A case study of three patients with chronic pruritus caused by liver disease describes them initially as suffering from “significant decreases in their quality of life, including lack of sleep, depression, inability to work, and suicidal ideations.” Been there; done that.
Happily for this trio, 5mg per day of THC at bedtime resolved the itch, and all of them were able to return to work. (One did remain depressed, however; maybe it was work that was the problem, or, you know, having a potentially fatal liver disease.)
These results are matched by lots of evidence, both anecdotal and clinical, from MS and chemotherapy patients.
At the level of basic science, a consensus seems to be emerging: Cannabinoids just might be good for itch. A 2009 overview of new research into endocannabinoid system and skin skin health wrote: “The ECS has a crucial role in central and peripheral processing, and in the control of such skin-derived sensory phenomena as pain and itch.”
This conclusion was based on a solid body of research suggesting that blocking the cannabinoid receptors induces itching in lab mice. (It’s a super complex topic, but a 2011 report gives a good overview of the research as well as more-or-less comprehensible introduction to recent revisions in how biologists understand and differentiate pain and itch.)
What about itching caused by plain old dry skin? There might even be evidence that cannabis topicals can help with that. But at this point we’re veering dangerously close to the realm of cosmetics and natural remedies—and we at RX are far too snobby to engage with any of that.