June 16, 2021

Exploring the Connection Between Psoriatic Arthritis and Bone Health

By Shivani Chinnappan, SWHR Programs Coordinator 

More than 8 million people in the United States are living with psoriasis, a chronic immune-mediated condition where skin cells multiply 10 times faster than the normal rate. This causes skin to build into raised patches or plaques, which may be red or discolored with white or silvery scales, depending upon the skin type. Although there are commonly impacted areas, psoriasis can present all over the body.  

In up to 30% of cases, patients will also develop psoriatic arthritis (PsA), inflammation in the joints where the tendons and ligaments connect to bone. Without a definitive diagnostic test and a shortage of rheumatology care in many locations, many PsA patients are not diagnosed in a timely fashion, resulting in delayed treatment that can worsen joint damage and related bone health issues. 

Some early symptoms of psoriatic arthritis include swelling or tenderness of joints (especially the fingers or toes), heel pain, swelling above the heel, and stiffness in the morning that improves over the day. Even though there is no specific test to diagnose psoriatic arthritis, health care providers can examine your joints for tenderness or your skin for abnormalities. A provider may conduct imaging tests like X-rays or MRIs to track changes in your joints or blood tests to rule out other conditions such as rheumatoid arthritis or gout.  

Although women and men are affected equally with PsA, studies indicate that women have worse patient-reported outcomes for pain, swollen joint count, responses to treatment, and remission. Women are more likely to experience polyarthritis (5 or more affected joints), greater self-reported impairment from joint pain, and worse experiences with fatigue than men.  

Research suggests that psoriatic arthritis may impact bone health, including development of bone erosions and bone spurs. Bone spurs occur where tendons attach to bones and may make it painful to move and cause additional joint inflammation. One study showed that PsA patients had significantly higher structural bone damage, with more bone erosions and more bone spurs than both healthy patients and those with psoriasis alone. The authors theorized that the chronic inflammation in PsA may play a role in speeding bone erosions.  

“While localized bone loss is a well-established as a key feature of PsA bone damage, studies also revealed lower bone mineral density and higher risk of bone fracture in [psoriasis] and PsA patients compared to healthy controls,” according to a review of the literature on bone remodeling in psoriatic disease. study of patients in the UK showed that those with psoriatic arthritis had an elevated risk of bone fracture than the general population. Another review found 13 of 21 published reports indicated increased bone loss in PsA patients, though the remainder did not. More research is needed to better understand the link between psoriatic arthritis and bone health as well as potential mechanisms — such as systemic inflammation — that may lead to these bone changes.  

Patients and providers should consider how potential treatments for psoriatic arthritis may influence bone health. For example, corticosteroids used to reduce inflammation may also weaken the bones. On the other hand, one study showed that PsA patients who took a biologic drug had denser, stronger bones compared to those who only used methotrexate (a disease-modifying anti-rheumatic drug) or patients with mild disease who were not taking any disease-modifying drug. 

For women, menopause also brings up intersecting issues with bone health and psoriatic arthritis. Menopause initiates the onset of significant bone loss in women due to the drop in estrogen in this life stage. Patients with psoriatic arthritis may experience loss of muscle mass due to inflammation, and research has shown that for postmenopausal women with PsA, this muscle atrophy was associated with increased occurrence of bone mineral loss.  

As women with PsA manage their condition, how can they also monitor and protect their bone health? Most therapies for psoriatic arthritis are safe for bone health, but patients should still discuss with their health care provider the best path forward to preserve bone health while treating inflammation and other symptoms. Patients can also take other precautions such as supplements of calcium and vitamin D to help prevent bone loss, and lifestyle interventions such as increasing exercise, reducing alcohol intake, and quitting smoking to help promote bone health. Read our piece on managing bone health in gynecological conditions for more about positive bone health practices. 

Researchers are still trying to determine the pathways and mechanisms that lead to psoriatic arthritis, which will in turn provide a clearer picture of the impact on bone health. Until then, patients can still live well by addressing symptoms that arise and identifying a personalized and holistic treatment plan that improves their quality of life.  

SWHR blog content on bone health is supported by a sponsorship from Amgen. SWHR maintains editorial control and independence over blog content.