A new cross-sectional study by a research team at the Seoul Medical Center Department of Internal Medicine in Seoul, Korea, was conducted with the objective of investigating the prevalence and clinical impact of of fibromyalgia (FM) in primary Sjögren’s syndrome (pSS) patients and to compare the clinical features of pSS patients with FM to those without FM.
The study, entitled “Prevalence and clinical impact of fibromyalgia in patients with primary Sjögren’s syndrome“ published online in the journal Clinical and Experimental Rheumatology, is coauthored by B. Choi, H. Oh, Y. Lee, and Y. Song — all of Seoul Medical Center, who note that clinical features of primary Sjögren’s syndrome overlap with those of fibromyalgia syndrome.
The investigators consecutively assessed one hundred pSS patients to identify the presence of FM according to American College of Rheumatology (ACR) 2010 criteria, with clinical and laboratory data collected from participant patients, all of whom satisfied American-European Consensus Group (AECG) criteria for pSS, and exclusion of thyroid dysfunction, infections or other chronic diseases.
Additional assessments included the EULAR Sjögren’s Syndrome Patient Reported Index (ESSPRI) which scores assessments of patients’ symptoms in primary Sjögren’s syndrome and the EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI) — a disease activity index for patients with primary Sjögren’s syndrome. Patient’s severity of depression was also measured by the Hamilton depression rating scale (HAM-D scale).
Sjögren’s Syndrome Foundation notes that Sjögren’s is a chronic autoimmune disease in which a person’s white blood cells attack their moisture-producing glands. The Foundation estimates that as many as four million Americans are living with this disease. The four primary symptoms associatrf with Sjögren’s are dry eyes, dry mouth, fatigue and joint pain, but the disease may also cause dysfunction of other organs such as the kidneys, gastrointestinal system, blood vessels, lungs, liver, pancreas, and the central nervous system. Patients may also experience extreme fatigue and joint pain and have a higher risk of developing lymphoma. The disease, first identified in 1933 by Dr. Henrik Sjögren, has been proven to affect virtually every racial and ethnic group.
According to an overview by Dr. Robert Fox and colleagues at the Scripps Clinic in La Jolla, California, cited by the Fibromyalgia Information Foundation Sjögren’s syndrome is a chronic disorder of unknown cause characterized by a particular form of dry mouth and dry eyes, with the loss of tears and saliva potentially resulting in characteristic changes in the eyes (called aqueous tear deficiency or keratoconjunctivitis sicca) and in the mouth with deterioration of the teeth, increased oral infection, difficulty in swallowing, and painful mouth.
They note that there are many different potential causes for dry eyes and dry mouth, but when they occur as a result of an autoimmune process, the condition is called Sjögren’s syndrome, which most frequently occurs in middle-aged women with a prevalence of about 1 in 500 persons. Sjögren’s patients may also have joint inflammation (arthritis), muscle inflammation (myositis), nerve inflammation (neuropathy), thyroid issues (thyroiditis), kidney inflammation (nephritis), or inflammation in other areas of the body, and may also experience severe fatigue and disruption of sleep patterns. Also, the blood of Sjögren’s patients may contain antibodies directed against normal cellular substances such as nuclear antigens and immunoglobulins, with the disease categorized as an autoimmune disorder to denote the apparent reaction of the immune system against the patient’s own tissues. Dr. Fox and his team observe that the trigger for this process remains unknown but speculate that it may be a virus.
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The National Fibromyalgia Association (NFA) describes fibromyalgia (FM) a common and complex chronic pain disorder that affects people physically, mentally and socially. In the past fibromyalgia has also been referred to as fibromyalgia syndrome, fibromyositis, and fibrositis. The condition is characterized by chronic widespread pain, multiple tender points, abnormal pain processing, sleep disturbances, fatigue and often psychological distress. Symptoms can wax and wain, with severe symptoms being extremely debilitating and disruptive of an individual’s basic daily activities.
The National Institutes of Health’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) notes that the word fibromyalgia comes from the Latin term for fibrous tissue (fibro) and the Greek ones for muscle (myo) and pain (algia)
The causes of fibromyalgia are unknown, but it is suspected that there are probably a number of factors involved. Many people associate the development of fibromyalgia with a physically or emotionally stressful or traumatic event, such as an automobile accident. Some connect it to repetitive injuries. Others link it to an illness. For others, fibromyalgia seems to occur spontaneously.
Researchers are examining other causes, including problems with how the central nervous system (the brain and spinal cord) processes pain. Some scientists speculate that a person’s genes may regulate the way his or her body processes painful stimuli. According to this theory, people with fibromyalgia may have a gene or genes that cause them to react strongly to stimuli that most people would not perceive as painful. There have already been several genes identified that occur more commonly in fibromyalgia patients, and NIAMS-supported researchers are currently looking at other possibilities.
Fibromyalgia is often considered an arthritis-related condition, but it is not truly a form of arthritis, which strictly speaking is a disease of the joints, because it does not cause inflammation or damage to the joints, muscles, or other tissues.
However, symptomatically fibromyalgia can mimic some characteristics of arthritis in that it causes significant pain and fatigue, and can interfere with a person’s ability to carry on daily activities. Also like arthritis, fibromyalgia is considered a rheumatic condition, a medical condition that impairs the joints and/or soft tissues and causes chronic pain. In addition to pain and fatigue, people with fibromyalgia may experience a variety of other symptoms including:
• Cognitive and memory problems (sometimes referred to as “fibro fog”)
• Sleep disturbances
• Morning stiffness
• Headaches
• Irritable Bowel Syndrome
• Painful menstrual periods
• Numbness or tingling of the extremities
• Restless Legs Syndrome (RLS)
• Temperature sensitivity
• Sensitivity to loud noises or bright lights.
A person may have two or more coexisting chronic pain conditions simultaneously, such as chronic fatigue syndrome, endometriosis, fibromyalgia, inflammatory bowel disease, interstitial cystitis, temporomandibular joint dysfunction, and vulvodynia, with it currently unknown whether these disorders share a common cause.
People with certain rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus (commonly called lupus), or ankylosing spondylitis (spinal arthritis) may be more likely to have fibromyalgia, as well.
The Fibromyalgia Information Foundation reports that there has been increasing recognition and interest recently that many patients with Sjögren’s syndrome have an additional crossover problem in the form of fibromyalgia, and some patients initially diagnosed with fibromyalgia also have Sjogren’s. However, the Foundation emphasizes that it is important for patients and their doctors to differentiate between symptoms due to Sjogren’s itself and symptoms due to fibromyalgia, as treatments respectively are often quite different. Furthermore, treatment of some features of fibromyalgia may actually make symptoms of Sjögren’s worse and vice versa.
Syndromes like fibromyalgia and Sjögren’s are notoriously difficult to diagnose because pain and fatigue can be associated with many different disorders. There are currently no diagnostic laboratory tests for fibromyalgia, with standard laboratory tests unable reveal a physiologic reason for pain, and because there is no generally accepted, objective test for fibromyalgia, some doctors unfortunately may conclude a patients pain is not real, or they may tell the patient there is little they can do.
Similarly, since symptoms of Sjögren’s can mimic other conditions and diseases, the disease can often be overlooked or misdiagnosed. On average, it takes nearly 3.9 years to receive a diagnosis of Sjögren’s, about which general awareness about Sjögren’s is still lacking and increased professional awareness is needed to help expedite new diagnoses and treatment options.
The Korean study reported in the Clinical and Experimental Rheumatology paper found that prevalence of FM was 31.0% (31/100) in pSS, and that widespread pain index and symptom severity scale were significantly correlated with ESSPRI and HAM-D scale in pSS. In multivariate analysis, ESSPRI and HAM-D scale were independently associated with increase of tender point count and symptom severity scale. ESSPRI was significantly higher in pSS patients with FM compared to those without FM, and the prevalence of FM in pSS patients with moderate-to-severe depression was significantly higher than those with mild depression or without depression. Serum 25-hydroxy vitamin D3 levels in pSS patients with FM were also significantly decreased compared to levels in those without FM.
The investigators conclude that their study confirms that fibromyalgia is prevalent coexisting with primary Sjögren’s syndrome, as well as being associated with higher ESSPRI and more severe depression.
Additional Resources:
National Center for Complementary and Integrative Health
National Institutes of Health
https://nccih.nih.gov/
Sjögren’s Syndrome Foundation
http://www.sjogrens.org/
American College of Rheumatology
http://www.rheumatology.org
Sjögren’s Syndrome: Articles by Dr. Robert Fox
http://www.robertfoxmd.com/SjogrensByFox/SjogrensByFox.php
Advocates for Fibromyalgia Funding, Treatment, Education, and Research
http://www.affter.org
Fibromyalgia Network
http://www.fmnetnews.com
National Fibromyalgia Association
http://www.fmaware.org
National Fibromyalgia Partnership, Inc.
http://www.fmpartnership.org
Arthritis Foundation
http://www.arthritis.org
Sources:
Clinical and Experimental Rheumatology
Sjögren’s Syndrome Foundation
National Institutes of Health’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Fibromyalgia Information Foundation
The National Fibromyalgia Association
Scripps Clinic