Study: Medical Marijuana Serves as Potential Therapy for Chronic Itch

Medical marijuana could potentially serve as an effective treatment for debilitating chronic itch, according to a study published in JAMA Dermatology. The study authors said that treating the condition has been difficult until now due to a lack of FDA-approved therapies.

“Chronic itch can be an especially difficult condition to treat, with off-label therapeutics often utilized,” said Shawn Kwatra, MD, assistant professor of dermatology at the Johns Hopkins University School of Medicine, in a press release. “With the increased utilization of medical marijuana and our knowledge of the role of the endocannabinoid system—a complex cell-signaling system that regulates a variety of functions in the body—in chronic itch, we decided to try medical marijuana with a patient who failed several therapies and had few options left.”

The researchers examined an African American woman over 60 years of age with a 10-year history of chronic itch. The patient had initial complaints of extreme pruritus on her arms, legs, and stomach. When given a skin examination, she presented with numerous hyperpigmented, raised skin lesions.

All of the treatment options offered to the patient had failed, including systemic therapies, centrally acting nasal sprays, steroid creams, and phototherapy. However, according to the investigators, the use of medical marijuana, either through smoking or in liquid form, provided the patient with an almost immediate improvement.

“We had the patient rate her symptoms using a numerical rating scale, where 10 is the worst itch and zero is no itch at all,” Kwatra said in the release. “She started at 10 but dropped to 4 within 10 minutes after initial administration of the medical marijuana. With continued use of the cannabis, the patient's itch disappeared altogether.”

The authors believe that tetrahydrocannabinol, one of the active ingredients in medical marijuana, attaches to brain receptors that influence the nervous system. This results decreased inflammation and nervous system activity, which could potentially lead to a reduction in skin sensations, including itchiness, according to the study.

The researchers said that further clinical trials are warranted to determine the efficacy of medical marijuana as an effective treatment for otherwise unmanageable chronic itch.

“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 in the release.

REFERENCE

Research news tip sheet: Story ideas from Johns Hopkins Medicine [news release]. EurekAlert; May 12, 2021. Accessed May 17, 2021. https://eurekalert.org/pub_releases/2021-05/jhm-rnt051221.php