Patients with inflammatory arthritis, including rheumatoid arthritis (RA), spondyloarthritis (SpA), and psoriatic arthritis (PsA), often experience varying degrees of fatigue during the course of their disease. As there is no medical test to clinically measure fatigue, understanding its effects on patients has proven to be a challenge, but it can be better understood through qualitative research.  

There are many different causes and contributing factors which make treating fatigue difficult. However, with a deeper understanding of the causes of fatigue in rheumatic conditions, physicians can better serve patients through a multidimensional approach.

 

What causes fatigue in inflammatory arthritis?

 

Patients often describe fatigue as being multidimensional, overwhelming, and unpredictable. This symptom can be broken down into physical fatigue (level of physical energy), emotional (level of distress), cognitive (concentration, aka “brain fog”), and living with fatigue (ability to carry out activities of daily living and social interactions), according to the authors of an article published in Rheumatology.

Choy EH, Dures E. Fatigue in rheumatoid arthritis. Rheumatology (Oxford). 2019;58(Suppl 5):v1-v2, Nov 2019. doi.org/10.1093/rheumatology/kez314.

 

 

In 2013, OMERACT (a nonprofit working to advance the design of qualitative studies in autoimmune and musculoskeletal diseases) developed the Bristol Rheumatoid Arthritis Fatigue Scale to qualify the symptom of fatigue for patients living with RA.

Fatigue is likely caused by a combination of clinical factors, note the Rheumatology authors, including pain, inflammation, and disability; psychosocial factors, including mood, coping ability, and behaviors; and personal factors, including job responsibilities, personal life, and comorbidities.

 

The link with chronic pain

 

According to a podcast by the National Psoriasis Foundation (NPF), chronic pain is a known contributing cause of fatigue that affects all facets of the symptoms itself.

Living with Chronic Pain and Fatigue in PsA and SpA; Psound Bytes Podcast. National Psoriasis Foundation. September 27, 2022.

Chronic pain can cause muscle fatigue leading to physical fatigue. However, it can also cause emotional and cognitive fatigue through a more central pathway. 

 

As well, pain is known to worsen disability, affect mood and coping skills, and lead to behavioral changes related to physical exercise and socialization, among others. All of these factors are known to affect fatigue.

According to the authors of the Rheumatology article, systemic inflammation leads to an increase in intracerebral IFN and TNF-α activity. (The Arthritis Association notes a strong correlation between inflammation and depression.

Arthritis and Mental Health. The Arthritis Foundation.

) The authors also state that there is a definite association between pain severity, psychosocial factors (such as depression), and fatigue. 

 

Sleep is also impacted in people who experience chronic pain. 

According to the NPF’s podcast, inflammatory arthritis patients with chronic pain often wake up not feeling rested. The quality of their sleep is often disrupted and they do not enter a deep sleep.

 

A multifaceted treatment approach

 

Treatment of fatigue in inflammatory arthritis can be just as complex as its cause. Treating pain appropriately can improve a patient’s ability to cope while improving functioning. This, in turn, improves symptoms of both depression and fatigue. 

According to the Rheumatology article, physical activity, psychosocial intervention, and biologic DMARDs (disease-modifying antirheumatic drugs) have demonstrated potential benefit in the treatment of fatigue in RA. Targeting the inflammatory markers and disease process through the use of biologic DMARDs can improve fatigue, although the use of them alone does not completely resolve the symptom. 

 

Self-management techniques through cognitive behavioral therapy have also been proven to improve fatigue, according to the Rheumatology authors. The theory is that by challenging one’s own thoughts and beliefs regarding goals and ability, a patient gains knowledge, coping strategies, and confidence leading to reactivation in everyday life. 

Treatment of fatigue in patients with inflammatory arthritis should be tailored to their specific needs depending on comorbidities (such as depression), functional ability, pain level, and disease control.