Fatigue is a common, under-recognized symptom of many inflammatory arthritis conditions such as RA, PsA and SpA, and can be broken down into physical fatigue, cognitive fatigue, and emotional fatigue.
The pathophysiology of fatigue in inflammatory arthritis is multifactorial and complex. Clinical, psychosocial, and personal factors all likely play a role.
Fatigue is recognized by patients with inflammatory arthritis as having a severe impact on quality of life. As the cause of fatigue is largely unknown, treatment remains a challenge, and a multifaceted approach should be considered.
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?
The underlying causes and pathophysiology of fatigue are not fully understood.
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.Related: Beyond the joints: Unraveling the psychological effects of arthritis
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.
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. Chronic pain can cause muscle fatigue leading to physical fatigue. However, it can also cause emotional and cognitive fatigue through a more central pathway.
Fatigue and myalgias are common in patients with chronic pain. Inflammation itself can cause pain and fatigue, and all three are closely linked.
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.) The authors also state that there is a definite association between pain severity, psychosocial factors (such as depression), and fatigue.
This means that inflammatory arthritis patients are at a higher risk of depression and experience more fatigue, and the effects on each other are likely cyclical and intertwined.
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.
Screening for and treating depression in patients with inflammatory arthritis can also improve their ability to cope while improving their functional ability, which can then affect their perceived 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.Related: Unmet need: What precision medicine can do for rheumatology
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.
What this means for you
Patients with inflammatory arthritis often suffer from an overwhelming sense of fatigue which can significantly affect quality of life. Physicians may want to screen for fatigue in this patient population, and assess for improvement throughout the course of treatment. Physicians can also advise patients on self-management of fatigue through tools such as cognitive behavioral therapy. Patients have identified fatigue as a priority to manage—therefore, we, as physicians, should prioritize it as well.
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