Controlling Psoriatic Arthritis — Can Cannabis Help?

Psoriatic arthritis is one of the most common forms of autoimmune arthritis. Because it produces often debilitating symptoms and there is no cure, it’s understandable why patients continue to seek complementary and alternative treatment options such as medical cannabis, especially given the unwanted side effects of prescription opioids for pain relief.

Individuals with psoriatic arthritis hope cannabis will provide relief for both pain and inflammation, but what does the science say about its viability as a treatment? And how can clinicians best help patients with psoriatic arthritis manage their symptoms and improve their quality of life?

Psoriatic Arthritis
Psoriatic arthritis is a systemic rheumatic disease that occurs in 30% to 40% of those with the autoimmune disease psoriasis. While psoriasis manifests on the skin, psoriatic arthritis manifests in the joints. Psoriasis is a chronic condition characterized by skin cell build-up, which forms itchy dry patches and scales. Persistent rashes on the skin, often on the knees or elbows, are itchy, painful, and, for some, embarrassing. The National Psoriasis Foundation estimates that nearly 8 million Americans are living with psoriasis and that chronic psoriasis symptoms can last for years or even a lifetime. While psoriasis typically presents before psoriatic arthritis, the reverse is true in 10% to 15% of patients.1

Signs and Symptoms
In addition to the rashes they experience, psoriasis patients who go on to develop psoriatic arthritis also experience swelling, pain, and stiffness in the joints along with the development of dactylitis—inflammation and swelling of an entire finger, toe, or extremity, sometimes called a “sausage digit.”2 Untreated, psoriatic arthritis can lead to permanent joint damage, and untreated chronic pain can lead to mental health disorders including anxiety and depression. Without management, the symptoms can significantly impair patients’ quality of life.

Beyond swelling, pain, stiffness in the joints, and the characteristic dactylitis, there are many symptoms that are unique to psoriatic arthritis. Fueled by an overactive immune system and excess inflammation, enthesitis may develop—inflammation directly where tendon meets bone in the elbows, knees, ribs, spine, pelvis, and other locations. They may also develop spondylitis—stiffness in the neck, back, and spine. Another common symptom associated with psoriatic arthritis is changes in the fingernails and toenails. The nails may become pitted, change color, or separate from the nail bed.

Diagnosis
It’s important for clinicians to be aware of and recognize these symptoms because no single test can confirm a diagnosis of psoriatic arthritis. A physician thus must rely on much of the medical exam, which typically examines the joints, fingernails and toenails, and soles of the feet, to help them make an accurate diagnosis.

In addition to the physical exam, imaging and laboratory tests are needed. X-rays and MRIs are used to look for physical changes in the joints that are characteristic of psoriatic arthritis, and laboratory tests are used to examine the levels of rheumatoid factor and uric acid present in joint fluid samples. A combination of the physical exam and imaging and lab tests helps rheumatologists diagnose a case of psoriatic arthritis.3

Treatment Options
Because there’s no cure, treatment options are aimed at controlling inflammation, pain, and other symptoms while improving patients’ quality of life. Over the past several years, treatment options have expanded,4 with more pharmaceutical and lifestyle options available than ever before.

In 2018, the American College of Rheumatology released treatment guidelines for psoriatic arthritis. On the lifestyle side, they emphasize the benefits that can be seen from physical therapy as well as management of lifestyle factors, including diet, exercise, and smoking cessation.

On the pharmaceutical side, the most common treatments include biologics, oral treatments, and, sometimes, off-label use of systemic therapies for other inflammatory diseases.2 In addition, nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and immunosuppressants may be used to manage inflammation and pain. In more severe cases, steroid injections and even joint replacement surgery may be necessary to address severely damaged joints.

It may take some time for patients and their physicians to find a combination of pharmaceutical and lifestyle interventions that partially or completely resolve all the manifesting symptoms. However, this delay in obtaining relief can leave patients frustrated. As a result, more and more patients with chronic pain and autoimmune diseases are interested in exploring alternative treatment methods such as cannabis and cannabinoid therapy. Increasing evidence supports the theory that the endocannabinoid system participates in the pathophysiology of arthritis-associated joint pain, suggesting that cannabinoid therapy may provide therapeutic relief for this unrelenting condition.5

Cannabis for Psoriatic Arthritis Treatment
Chronic and severe pain remains one of the most common reasons for the medical use of cannabis. Many of those who report using medical cannabis for pain choose to do so in order to avoid or decrease their reliance on opiates and other pain-relieving medications.6 Patients with chronic arthritis and musculoskeletal pain tend to be the most prevalent users of therapeutic cannabis products, both to relieve pain and reduce inflammation. While clinical evidence is just starting to catch up to longstanding anecdotal reports that cannabis helps relieve arthritis pain driven by inflammation, arthritis is a qualifying condition for medical cannabis programs across the country. Programs in some states, including Connecticut, specifically list psoriatic arthritis as a qualifying condition for the use of medical cannabis.

There are very few studies that examine the medical use of cannabis for the management of psoriatic arthritis specifically. Following is a review of the science of cannabis treatment options for chronic pain and inflammation.

Chronic Pain
The chronic, often debilitating pain associated with psoriatic arthritis can take not only a physical toll but also a mental one. Psoriasis patients have an increased risk of developing depression, anxiety, and suicidal thoughts. In a population-based cohort study, they were 39% more likely to be depressed and 31% more likely to experience anxiety.7 These additional risks mean that it’s even more important for clinicians to have an honest discussion with their patients who want to explore medical cannabis options to improve outcomes and quality of life.

Preliminary evidence supports cannabis as a therapeutic and the endocannabinoid system as a target for the treatment of chronic pain. In a review published in Current Neuropharmacology examining the role of the endocannabinoid system in pain control, authors concluded that synthetic and naturally derived cannabinoids, especially THC and CBD, hold promise for alleviating pain that’s otherwise resistant to treatment, such as neuropathic, inflammatory, and oncologic pain.8

Unfortunately, there remains a significant gap between available clinical studies and anecdotal reports from patients, suggesting a critical need for rigorous research to ensure safe and effective use of cannabis for this population.9

While it remains well established that cannabis can be useful in controlling chronic pain for medical users, more research is needed to determine how safe and effective it is for managing the symptoms of psoriatic arthritis specifically and to establish the most effective cannabis application method—whether topical, sublingual, or oral—or a combination of methods.

Inflammation
Psoriatic arthritis, a rheumatic disease, benefits from the studies done to examine cannabinoids in the treatment of all rheumatic diseases. Many of these studies have found cannabinoids to be key players in the reduction of inflammation in the body. In a 2019 article published in Current Opinions in Rheumatology, study findings indicated that cannabinoids may have anti-inflammatory effects through activation of CB2 receptors, which “decrease cytokine production and immune cell mobilization.”10 It was noted that it’s important to keep in mind which receptors are being targeted by each cannabinoid in order to discover the most suitable treatment, but nonintoxicating CBD demonstrated antiarthritic effects independent of cannabinoid receptors.

A 2019 review published in Autoimmunity Reviews weighed the pros and cons of medical cannabis use and found that cannabinoids’ anti-inflammatory and immunomodulatory properties may be responsible for their relief of pain and other symptoms in rheumatic disorders.11 The authors observed that while there are many commonly established and already studied medications that help manage inflammation, including commonly used biologics, there are far fewer treatment options for chronic pain. Because rheumatic disorders typically display both inflammation and pain as primary symptoms, this makes cannabinoids, which may help both, a particularly promising therapeutic option.

While there’s preliminary evidence to support the use of medical cannabis to manage both inflammation and pain, very little evidence has established what’s most beneficial when it comes to various cannabinoid profiles, strains, or phenotypes; cannabis application methods; and synthetic vs naturally occurring cannabinoids. Preliminary evidence suggests that both CBD and THC can be effective options. In a 2018 cohort study published in the Journal of Headache and Pain, patients reporting chronic pain preferred a high-THC, low-CBD strain with various terpenes present, which the authors posited was due to the “potent analgesic, anti-inflammatory, and antiemetic properties of THC, with anti-inflammatory and analgesic properties of beta-caryophyllene and beta-myrcene.”12

Practical Recommendations for Clinicians
Clinicians should always work within their scope of practice and with cannabis’ legal status in their state in mind. The decision to recommend medical cannabis for certain conditions is increasingly being left to the clinical judgment of the provider, especially in states that describe a qualifying condition as “any condition for which treatment with medical marijuana would be beneficial, as determined by the patient’s physician.”

Preliminary evidence suggests that cannabinoid therapy may be beneficial for those suffering from autoimmune and inflammatory conditions such as psoriasis and psoriatic arthritis by suppressing systemic inflammation and taming chronic pain. However, evidence also suggests that managing inflammatory lifestyle diseases requires a multifaceted approach and that cannabinoid therapy may only be a piece of the puzzle.13

Col. Philip Blair, MD, a family medicine physician who uses CBD to manage inflammatory disease, suggests that the best approach to managing chronic inflammatory disease comes from utilizing a multidisciplinary team approach to produce sustainable lifestyle changes, including stress management, physical activity, medical nutrition therapy, and cannabinoid therapy.14

It’s important for health care providers to understand that medical cannabis may be a viable method of treatment for their patients who want to use, or are already using, cannabis to manage the symptoms of their autoimmune-driven psoriatic disease.

While there’s not enough evidence to support specific cannabinoids, ratios, or application methods, practitioners can educate patients appropriately and use clinical judgment to trial various options and dosages until the patient finds a solution that provides optimal pain and symptom relief. Clinicians must treat the patient, not the condition, and remember that cannabinoid therapy is a highly personalized medical strategy.

— Emily Kyle, MS, RDN, CDN, CLT, HCP, is a registered dietitian nutritionist and certified holistic cannabis practitioner. As a three-time published cookbook author, she combines the medicinal, nutritional, and culinary aspects of cannabis use through the creation of detailed cannabis-infused recipes. She advocates for responsible adult-recreational cannabis use and shares her published resources at EmilyKyleNutrition.com and on Instagram at @EmilyKyleNutrition.

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