Chronic itching - known clinically as chronic pruritus - is characterized as a relentless and sometimes even debilitating sensation of itching and often lowers the quality of life for those who suffer from it.
Treating the condition has been difficult because there are few Food and Drug Administration-approved therapies. Now, a recent case study by researchers at Johns Hopkins Medicine provides evidence that there may already be a promising option available for patients with chronic itching: medical marijuana (cannabis).
"Chronic itching can be a particularly difficult condition to treat, often using off-label therapies," said Shawn Kwatra, MD, assistant professor of dermatology at Johns Hopkins University School of Medicine. “With the increased use 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 itching, we decided to try medical marijuana in a patient who failed several therapies. and had few alternative options. ”
The recent study examined an African American woman in her 10s who had been suffering from chronic itching for XNUMX years. The patient initially arrived at the Johns Hopkins Itch Center with severe pruritus symptoms in her arms, legs and abdomen. A skin examination revealed numerous hyper-pigmented, raised skin lesions. Various treatments were applied to the patient - including various systemic therapies, centrally acting nasal sprays, steroid creams, and phototherapy - but all failed.
The use of medicinal marijuana immediately improved chronic itching
The researchers say that using medical marijuana - either through smoking or in liquid form - gave the woman an almost immediate improvement.
“We had the patient rate her symptoms using a numerical rating scale, with 10 being the worst itch and zero being no itch at all,” says one of the researchers. “She started at a grade of 10, but dropped to a grade of itchiness of 10 within 4 minutes after the first administration of the medical marijuana. With continued use of the cannabis, the patient's itching disappeared completely. ”
The researchers believe that one of the active ingredients in medicinal marijuana, tetrahydrocannabinol — commonly known by its abbreviation THC — attaches to brain receptors that affect the nervous system. When this happens, inflammation and nervous system activity decrease, which can also lead to a reduction in skin sensations such as itching.
Although there are still conclusive research should be done to validate medical marijuana as an effective measure for the relief of previously uncontrollable itching, it is believed that further clinical studies are certainly warranted.
"Controlled studies are needed to determine the dosage, efficacy and safety of medical marijuana in the treatment of various human itching subtypes, and once these are conducted we will better understand which patients are most likely to benefit from this therapy."
Also at the National Library of Medicine research results on the treatment of chronic itching
Medical marijuana is becoming widely available to patients in the United States, and now that recreational marijuana is legalized in many states, patient interest is on the rise. The endocannabinoid system plays an important role in skin homeostasis, in addition to broader effects on neurogenic responses such as pruritus and nociception, inflammation and immune responses.
Numerous studies of in vitro and animal models have provided insight into the possible mechanisms of cannabinoid modulation on pruritus, with the most evidence behind neuronal modulation of peripheral itch fibers and centrally acting cannabinoid receptors.
In addition, studies in humans, while limited due to differences in the cannabinoids used, disease models and method of administration, have consistently shown a significant reduction in both scratching and symptoms in chronic itching.
Clinical studies have shown a reduction of pruritus in various dermatological (atopic dermatitis, psoriasis, asteatotic eczema, prurigo nodularis and allergic contact dermatitis) and systemic (uremic pruritus and cholestatic pruritus) diseases.
These preliminary human studies warrant controlled studies to confirm the benefit of cannabinoids in the treatment of pruritus and to standardize treatment regimens and indications. In patients who have refractory chronic pruritus after standard therapies, cannabinoid formulations can be considered as an adjuvant therapy when legal.
Thus the report of the investigation into chronic itching at the National Library of Medicine.