Cannabinoids cure Pruritus
Itching (pruritus) is a common symptom associated with numerous skin diseases, as well as a secondary symptom of numerous serious conditions such as renal failure and liver disease. Itching, typically goes untreated by standard medical therapies.
A review of the scientific literature reveals three clinical trials investigating the use of cannabinoids in the treatment of pruritus. Writing in the August 2002 issue of the American Journal of Gastroentrology, investigators from the University of Miami Department of Medicine reported successful treatment of pruritus with (5 mg) of (THC) in three patients with cholestatic liver disease. Prior to cannabinoid therapy, subjects had failed to respond to standard medications and had lost their ability to work. Following evening cannabinoid administration, all three patients reported a decrease in pruritus, as well as “marked improvement” in sleep and were eventually able to return to work. Resolution of depression was also reported in two out of three subjects. “Delta-9-tetrahydrocannabinol may be an effective alternative in patients with intractable cholestatic pruritus,” investigators concluded.
The following year, British researchers reported in the June 2003 issue of the journal Inflammation Research that the peripheral administration of the synthetic cannabinoid agonist (HU-211) significantly reduced experimentally-induced itch in twelve subjects. Investigators had previously reported that topical application of (HU-210) on human skin reduced experimentally-induced pain and acute burning sensations.
Most recently, researchers at Wroclaw, Poland’s University of Medicine, Department of Dermatology, reported that application of an endocannabinoid-based topical cream reduced uremic pruritus and xerosis (abnormal dryness of the skin) in hemodialysis patients. Three weeks of twice-daily application of the cream “completely eliminated” pruritus in thirty eight percent of trial subjects and “significantly reduced” itching in others. Eighty-one percent of patients reported a “complete reduction” in xerosis following cannabinoid therapy.
In light of these encouraging preliminary results, some dermatology experts now believe that cannabinoids and the cannabinoid system may represent “promising new avenues for managing itch more effectively.”
 Neff et al. 2002. Preliminary observation with dronabinol in patients with intractable pruritus secondary to cholestatic liver disease. American Journal of Gastroenterology 97: 2117-2119.
 Dvorak et al. 2003. Histamine induced responses are attenuated by a cannabinoid receptor agonist in human skin (PDF). Inflammation Research 25: 238-245.
 Dvorak et al. 2003. Cannabinoid agonists attenuate capsaicin-induced responses in human skin. Pain 102: 283-288.
 Szepietowski et al. 2005. Efficacy and tolerance of the cream containing structured physiological lipid endocannabinoids in the treatment of uremic pruritus: a preliminary study. Acta Dermatovenerologic Croatica (Croatia) 13: 97-103.
 Paus et al. 2006. Frontiers in pruritus research: scratching the brain for more effective itch therapy. Journal of Clinical Investigation 116: 1174-1185.
A woman’s debilitating chronic itch disappeared after she started using marijuana
A woman’s chronic itch defied all types of treatment, from steroids to opioids to light therapy, but it finally dissipated after her doctors told her to try cannabis.
The woman had dealt with chronic itch symptoms — medically known as chronic pruritus — for a decade, according to a report published April 9 in the Journal of the American Medical Association (JAMA) Dermatology.
Chronic pruritus specifically refers to itching that persists for more than six weeks, and the symptom can be associated with a variety of diseases, including eczema, hyperthyroidism and certain nerve disorders, according to a 2013 report in the New England Journal of Medicine (NEJM). In the woman’s case, her pruritus derived from a disease of the bile ducts of the liver called primary sclerosing cholangitis.
There are several theories as to how this disease leads to itchiness but generally, the condition disrupts the normal production of bile, which can lead to a buildup of irritating chemicals under the skin, according to “Itch: Mechanisms and Treatment” (CRC Press/Taylor & Francis, 2014).
Due to her bile duct condition, the woman also developed lichen amyloidosis, in which raised, dark, itchy bumps appear on the skin and sometimes meld together into thick plaques. The woman had these plaques on her trunk and limbs, accompanied by “extreme” itchiness.
The woman’s primary sclerosing cholangitis was kept under control with medicine and remained stable through time, but her itchiness did not improve. Doctors had previously prescribed a laundry list of treatments to combat this pervasive itching, including topical and oral corticosteroids; an opioid nasal spray; naltrexone, which works against the effects of opioids; and phototherapy, which involves exposing the affected skin to ultraviolet light.
When all these treatments proved unsuccessful, her doctors turned to medical cannabis. Previous studies have hinted that topical and synthetic cannabinoid treatments can provide at least some relief from itchiness, they noted in the JAMA report. In addition, laboratory studies in animals and cells have hinted at possible explanations as to how the drugs dial down itchy sensations, according to a 2020 review in Journal of the American Academy of Dermatology
They recommended she use cannabis two nights a week, either by smoking medical marijuana with 18% tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, or by taking cannabis in tincture form by placing a liquid extract under her tongue.
“Within 10 minutes after the initial administration, her Worst Itch Numeric Rating Scale (WI-NRS) score improved from 10 of 10 to 4 of 10,” her doctors wrote in the JAMA report. This scale ranges from 0 (“no itch”) to 10 (“worst imaginable itch”).
The doctors followed up with the woman after five months of treatment and then again after a full year, and they found that she consistently rated her average daily itchiness as 4 out of 10, a drastic improvement from her previous 10 out of 10. At the 16-month and 20-month follow-ups, her itchiness rating plummeted even lower, falling to 0 out of 10.
“Aside from mild sedation, she reported no adverse effects,” her doctors wrote. In addition, “she reported an improvement in quality of life,” based on a scoring system called the Dermatology Life Quality Index. She was also able to stop taking her other prescribed medications.
The exact mechanism by which cannabis reduced the woman’s itching is unknown, but her doctors presented several theories.
For instance, THC binds to various receptors in the endocannabinoid system, increasing the activity of some while decreasing that of others. The activation of CB1 receptors in the spinal cord and brain, and of both CB1 and CB2 receptors in nerves elsewhere in the body, has been associated with increased pain thresholds, lower nerve cell activation and decreased inflammation, they wrote. In addition, a receptor called TRPV1 helps trigger our sensation of itch, and cannabinoids lock this receptor into a “closed” position, effectively blocking its itch signals.
While this particular patient benefited from the use of cannabis with minimal side effects, the risks and benefits of the treatment still need to be assessed on a larger scale, “especially in its various routes of administration,” the doctors wrote. Cannabinoid use has been linked to cognitive impairment, loss of motor coordination, and when smoked, chronic bronchitis symptoms, they wrote in the study.
So while the results of the woman’s case are “promising … randomized clinical trials are needed to confirm the results,” the doctors wrote. Other researchers have called for such trials in the past, in order to evaluate the benefits of cannabis for chronic itch and to standardize dosing and the course of treatment, according to the Journal of the American Academy of Dermatology report.
Originally published on Live Science.
Nicoletta Lanese is a staff writer for Live Science covering health and medicine, along with an assortment of biology, animal, environment and climate stories. She holds degrees in neuroscience and dance from the University of Florida and a graduate certificate in science communication from the University of California, Santa Cruz. Her work has appeared in The Scientist Magazine, Science News, The San Jose Mercury News and Mongabay, among other outlets.
Cannabis Creams Show Promise In Relieving Itch In Some Skin Diseases
AURORA, Colo. (CBS4)– Researchers at the University of Colorado Anschutz Medical Campus say the chemical compounds found in marijuana contain anti-inflammatory properties that could make them useful in the treatment of eczema, psoriasis, atopic and contact dermatitis.
This new study, published online recently in the Journal of the American Academy of Dermatology, summarizes the current literature on the subject.
Currently, 28 states allow comprehensive medical cannabis programs with close to one in 10 adult cannabis users in the U.S. utilizing the drug for medical reasons.
As researchers examine the drug for use in treating nausea, chronic pain and anorexia, more and more dermatologists are looking into its ability to fight a range of skin disease.
At Lightshade marijuana dispensary in Denver, customers can find creams and balms infused with THC and CBD, compounds found in marijuana. Many of the products promise pain relief.
“They can have an item that has no psychosis effect to it, just relief… relief of muscle, relief of skin,” said Devo Beck, General Manager of Operations for Lightshade.
CBS4 Health Specialist Kathy Walsh interviews Lightshade general manager of operations Devo Beck (credit: CBS)
Right now, there are no large-scale clinical trials on humans that prove those claims.
“I can say a very high percentage of our customers, including myself, including our employees, have full relief from these products,” said Beck.
“We did not study pot creams, we studied all of the literature surrounding these creams,” explained the study’s senior author Dr. Robert Dellavalle, MD, associate professor of dermatology at the University of Colorado School of Medicine.
Dellavalle concluded the topical treatments containing the cannabis compounds show a promising role in the treatment of itch associated with skin diseases.
CBS4 Health Specialist Kathy Walsh interviews Robert Dellavalle, MD, associate professor of dermatology at the University of Colorado School of Medicine (credit: CBS)
“There is tremendous potential for a new class of medications to treat itch and inflammation that is not a steroid and is not an opioid,” said Dellavalle.
Dellavalle cautioned that large-scale clinical trials still need to be done, but Beck is already a believer.
“We see the results on a daily basis,” Beck said.
Kathy Walsh is CBS4’s Weekend Anchor and Health Specialist. She has been with CBS4 for more than 30 years. She is always open to story ideas. Follow Kathy on Twitter @WalshCBS4.