Cannabinoids in Dermatology: What Research Says About Psoriasis, Eczema and More

Cannabinoids, the active compounds in the cannabis plant, are being studied as a possible treatment for inflammatory skin conditions like psoriasis, eczema (atopic dermatitis) and acne. Research suggests they may help calm inflammation, regulate oil production and ease itching, although most of the evidence so far comes from lab and animal studies.

The endocannabinoid system (ECS), found throughout the human body, plays a key role in regulating a range of physiological functions, including in the skin. Made up of cannabinoid receptors (CB1 and CB2), endocannabinoids and enzymes, this system is involved in processes like inflammation, cell proliferation and apoptosis (programmed cell death), all of which matter for skin health.

Dermatology researchers have explored cannabinoids for conditions such as psoriasis, acne, atopic dermatitis and skin inflammation. Studies suggest cannabinoids may help reduce inflammation, regulate sebum production and relieve itching and pain.

How medical cannabis is being used in dermatology

As medical cannabis keeps getting legalized in more places, more people are turning to cannabis compounds like tetrahydrocannabinol (THC) and cannabidiol (CBD) for skin conditions.

That creates a new challenge for dermatologists, who, according to researchers at the George Washington University School of Medicine and Health Sciences, still aren't fully involved in the decisions consumers make about these products.

What studies say about medical cannabis for skin

In a peer-reviewed study published in the Journal of Drugs in Dermatology (JDD), the researchers point out that consumers “are interested in and using MCP [medical cannabis products] for dermatologic indications, most commonly for inflammatory skin disorders.”

However, they note that many of these uses aren't prescribed by dermatologists, which underlines the need for skin doctors to get more familiar with these products and their potential applications.

“Dermatology is no exception when it comes to ongoing research into medical cannabis and its implications for treating inflammatory and neoplastic skin disease. For example, medical cannabinoids have been approved in several states for dermatologic conditions such as cutaneous lupus, nail-patella syndrome, neurofibromatosis and psoriasis,” the researchers write.

Adam Friedman, professor and chair of the Department of Dermatology at George Washington University, puts it this way: “This study highlights and provides evidence of consumer support for these skincare products. Consumers and patients are already using MCP to treat inflammatory skin conditions like acne, rosacea, atopic dermatitis and psoriasis, even without a dermatologist's guidance.”

What does medical cannabis use mean for dermatologists?

With MCP use on the rise, dermatologists need proper training on these products. That way they can guide patients more effectively and make sure the products are used safely and actually help.

Bringing MCP into dermatology could open new treatment options for a range of skin conditions and improve quality of life for many patients.

Can cannabis help with psoriasis? Potential skin benefits

Psoriasis is a common chronic inflammatory skin disease marked by overgrowth and shedding of keratinocytes (the main cells of the outer skin), infiltration of T cells and neutrophils, and activation of dendritic cells and macrophages.

The full mechanism behind psoriasis isn't completely understood, but immune cell dysregulation in the skin, particularly involving Th1 and Th17 cells, has been shown to play a critical role.

Right now the evidence for topical Cannabis sativa L. preparations in psoriasis is only anecdotal, but the therapeutic possibilities of cannabinoids are broad.

They act through CB2 receptors and through mechanisms independent of the classic cannabinoid receptors to regulate Th1 and Th17 lymphocytes (Derakhshan and Kazemi, 2016). On top of that, some phytocannabinoids inhibit keratinocyte proliferation through pathways independent of CB1 and CB2 (Wilkinson and Williamson, 2007).

Atopic dermatitis (eczema): cannabis's potential for treating flare-ups

Atopic dermatitis (AD), better known as eczema, is the most common chronic inflammatory skin disease, triggered and driven by a mix of genetic, environmental and immune factors. Symptoms include dry skin, redness, oozing, crusting, thickened skin (lichenification) and intense itching.

Skincare products made with Cannabis sativa L. seed oil are marketed for AD, but hemp seed oil contains no cannabinoids or other bioactive phenolic compounds, so its benefit is basically limited to moisturizing the skin.

Preclinical studies, however, indicate that cannabinoids have strong therapeutic potential for AD. Selective CB1 agonists inhibit mast cell activation and histamine release. Topical application of anandamide analogs reduces skin inflammation in animal models of AD (Kim et al., 2015).

Selective CB2 agonists have also been shown to inhibit IgE-mediated skin inflammation and spontaneous itching in AD models (Maekawa et al., 2006).

Cannabis and fibrotic skin diseases like scleroderma

Scleroderma, or systemic sclerosis (SSc), is a rare autoimmune disease characterized by fibroblast dysfunction, small-vessel disease and an immune response that produces pro-inflammatory cytokines and autoantibodies. SSc shows up as progressive thickening and fibrosis (scarring) of the skin.

Recent evidence suggests that genetic and pharmacological manipulation of the endocannabinoid system modulates the fibrotic response. CB1 and CB2 receptors behave differently in experimental models of dermal fibrosis.

Inactivating CB1 prevents fibroblast activation and has an antifibrotic effect (Marquart et al., 2010), while activating CB2 prevents skin fibrosis and the infiltration of leukocytes into tissue (Akhmetshina et al., 2009).

PPARγ agonists block the profibrotic response by inhibiting the TGFβ signaling pathway. Dual PPARγ/CB2 agonists show potent anti-inflammatory and antifibrotic activity in experimental models of SSc (Del Río et al., 2016).

The bottom line on medical cannabis and skin care

Research on cannabinoids for skin disease is evolving fast. Cannabinoids look like promising treatment options for conditions like psoriasis, atopic dermatitis and fibrotic skin diseases. Still, clinical trials are needed to confirm these preclinical results and establish that they're effective and safe in humans.