The endocannabinoid system is functional in the skin, responsible for many aspects of skin homeostasis, and offers potential targets for the management of inflammatory skin conditions, according to a literature review.
“Cannabinoids represent a broad class of chemical compounds originally comprised only of phytocannabinoids — cannabinoids produced by the cannabis plant,” co-author Adam Friedman, MD, FAAD, at George Washington University School of Medicine and Health Sciences, told Healio Dermatology in an interview. “The study of these plant-derived cannabinoids led to the discovery of the endocannabinoid system, naturally produced cannabinoids in humans and animals.”
Preclinical and early clinical research has found multiple applications for cannabinoids in the management of inflammatory and neoplastic skin diseases, but well-designed and controlled studies are needed, he said.
The researchers utilized PubMed and clinicaltrials.gov for articles relevant to cannabinoids, skin conditions and other disease-specific search terms.
Activating the endocannabinoid system in the skin reduces inflammation and “plays a role in regulating keratinocyte proliferation and differentiation, which are pathologically increased in psoriasis,” they wrote.
In atopic dermatitis and other inflammatory skin conditions, cannabinoids have anti-inflammatory and antipruritic effects and may offer possible therapies. In trials of patients with atopic dermatitis, the use of topical palmitoylethanolamide and cannabinoid emulsions increased the time between flares and reduced relapses.
In seborrheic dermatitis, 11 patients treated with a 3% Cannabis seeds cream saw a significant decrease in erythema and sebum production compared with control subjects. Additionally, a current clinical trial assessing cannabidiol to treat tremor in Parkinson’s disease is also assessing the efficacy of cannabidiol in treating seborrheic dermatitis, according to the researchers.
“Because of their ability to modulate lymphocyte proliferation and cytokine release, cannabinoids have been proposed as therapeutic agents to help prevent [graft-versus-host disease] presentation in the skin,” they wrote.
In treating acne, the endocannabinoid system may “suppress cell proliferation” and “pro-inflammatory cytokine elevation,” and cannabinoids should be considered as possible therapeutic agents in future clinical trials, they wrote.
“Sadly, due to the restrictive regulatory environment that labeled all cannabinoids derived from the cannabis plant, regardless of psychoactive properties, as Schedule I, we are decades behind where we should be with clinical translation,” Friedman said. “For now, with over two-thirds of the U.S. approving medical cannabis for a broad array of indications, our oversight is limited. We can only at most recommend (requiring registering with one’s state program and fulfilling their requirements), not prescribe, and it ultimately falls on the dispensaries to provide formulations based on the patient’s direction and complaints.”
He recommends clinicians be up to date on their knowledge of these ingredients to provide evidence-based recommendations to patients. – by Abigail Sutton
Disclosures: The authors report no relevant financial disclosures.