Fibromyalgia (FM) is a chronic health condition whose core symptoms include widespread pain, sleep disturbances, and fatigue; it is associated with comorbid headaches, irritable bowel syndrome, interstitial cystitis, chronic pelvic pain, temporomandibular pain disorder, restless legs syndrome, systemic exertion intolerance disease, and psychological distress. FM disproportionately affects women and its prevalence in the US is between 2% and 8%.1 Because of the litany of often severe symptoms, people afflicted with FM are routinely referred to subspecialists before receiving an accurate diagnosis, seeing three to four medical providers over more than 2 years.2,3 Such a delay in diagnosis may occur because of FM's complicated presentations and a lack of unified diagnostic guidelines even among FM experts and advanced practice registered nurses (APRNs). The objective of this article is to provide APRNs with a practical approach to recognize and treat FM.
CASE STUDY
SJ is a middle-aged female presenting to you, the APRN, with chronic left knee pain.
She reports difficulty walking long distances, and stiffness and instability when rising from sitting. "I don't trust my knee anymore." She takes acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) as needed. She has undergone 6 months of physical therapy and received two corticosteroid injections to her left knee by orthopedics with suboptimal relief.
A chart review shows that SJ has seen specialists for migraines and restless leg symptoms (neurology), irritable bowel syndrome (gastroenterology), insomnia (sleep specialist), and chronic pelvic pain and dysmenorrhea (gynecology) unrelieved by hysterectomy.
Diagnosing fibromyalgia: rule in (not out)
Providers should consider using a four-step approach to identifying and diagnosing FM, defined by clinical recognition of chronic pain and nonpain symptoms of FM; simple screening tests that specifically target FM; and formal diagnostic testing.
SJ: "Fibromyalgia? That's what doctors say when they don't know what else is happening - a wastebasket diagnosis."
Step 1: Recognizing FM pain and nonpain symptoms and comorbidities
Initial steps require recognizing FM symptoms and ruling out other conditions. Pain is at least 3-6 months in duration-the longer the timeframe, the less likely the etiology is more serious or easily detectable (for example, cancer, endocrine imbalance).3,4 Further, when analyzing pain and nonpain symptoms that characterize FM, providers should take into account comorbid disorders (see Recognizing common symptoms of FM and comorbidities). Chronic pain symptoms of FM are highlighted separately because recent criteria have excluded common pain symptoms, such as tenderness and morning stiffness historically observed in patients with FM.5 Of the seven common FM pain symptoms, SJ endorses "tender all over," "headaches," and "pain sensitivity." Of chronic nonpain symptoms, SJ reports "trouble sleeping" and "feeling tired all of the time." She also reports "tenderness to touch" and "sensitivity to bright lights"-symptoms that distinguish FM from clinical depression, which can manifest similar symptoms to FM, such as, "cognitive/memory" fatigue and unrefreshed sleep symptoms. Recognizing cardinal FM symptoms in their patients will aid APRNs in being proactive by ruling in the possibility of an FM diagnosis, rather than considering it a so-called diagnosis of exclusion.
Step 2: Applying screening test for suspicion of FM
A second step is to use a simple screening test that can be performed as part of other routine evaluation of all patients with chronic pain.6 One screening tool is conducted with two tests: 1) Reports of pain with application of 4 kg of pressure over 4 seconds (or when the examiner's nail beds blanch) to the Achilles tendons, and 2) Yes/No response to the question: "I have a persistent deep aching over most of my body" (see Screening for FM). The "deep ache question" is emblematic of FM pain/tenderness phenotype characterized by the pain's persistence, depth, and diffuseness, and demonstrates a sensitivity and specificity of 92% and 80%, respectively.7
Step 3: Ruling out major medical diagnoses and scheduling a follow-up visit
Pain, though not necessarily due to FM, is the leading cause of outpatient visits among middle-aged and older adults.8 Patients may be seen for other reasons (for example, osteoarthritis, acute back pain, hypertension, diabetes, skin disorders, and asthma); however, patients whose chief concern is a problem other than FM will likely require follow-up visits to diagnose FM. If other pain disorders are identified, FM can be responsible for amplifying pain from central sensitization (for example, SJ's knee pain may be heightened by underlying FM). Because lab tests and imaging are nondiagnostic for FM, select tests ordered at the initial visit may be helpful in ruling out other conditions, as informed by history and physical exam. Basic lab evaluation may include complete blood cell count, comprehensive metabolic panel, thyroid-stimulating hormone, 25-hydroxy vitamin D, erythrocyte sedimentation rate, and C-reactive protein in order to rule out hematologic, electrolyte, metabolic, inflammatory, or vitamin deficiency syndromes. Serologic studies, like antinuclear antibody, rheumatoid factor assays, complement proteins, or enzyme-linked immunosorbent assay test (Lyme disease), are generally avoided unless risk factors or certain signs or symptoms are present (for example, prolonged joint stiffness, synovitis, family history of autoimmune disorder, history of tick bites). Imaging studies, such as radiography, ultrasound, computed tomography, and MRI depend upon subjective and objective findings, previous imaging findings (if applicable), and past or recent trauma or surgeries.9
Step 4: Confirming FM with formal diagnostic criteria
The fourth step is to apply a formal diagnosis procedure. The 2016 revisions to the American College of Rheumatology (ACR) 2010/2011 preliminary diagnostic criteria for FM is currently most widely used.10 The more recent modified Fibromyalgia Assessment Status (FAS) and the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society (ACTTION-APS) Pain Taxonomy (AAPT) are comparable and more user-friendly.11,12 In practice, most clinicians use their informed clinical judgment rather than formal criteria in FM diagnosis. Once diagnosed, a useful instrument for assessing a patient's level of FM severity, functioning, or progress is the Revised Fibromyalgia Impact Questionnaire (FIQR), which takes under 2 minutes to administer (see FIQR).13
Pathophysiology, genetic predisposition, and environmental triggers
FM is a nociplastic pain disorder assumed to be driven by central sensitization. "Centralized" refers to the central nervous system as the source of the symptoms or as the cause of symptom amplification. This term does not imply that peripheral nociceptive input (for example, damage or inflammation of body regions) is not contributing to pain experienced by individuals with FM, but instead that more nociceptive input is felt than would be anticipated based on input.14 FM is often lifelong, manifested in childhood as regional pain (headaches, abdominal pain, musculoskeletal pain).15,16 FM is also genetic: twin studies suggest a 50% genetic and environmental risk of developing FM and related conditions, like irritable bowel syndrome or headache.17 Environmental factors capable of triggering symptom onset in persons genetically predisposed to chronic pain include infections (for example, viral hepatitis), trauma (for example, motor vehicle collisions), or stress (for example, combat).18-20 Critical for APRNs to understand is the concept of central sensitization, genetic predisposition, and environmental triggers, as individuals with FM are disproportionately subjected to procedures and surgeries (for example, hysterectomy, joint replacement) in the hope of curing pain.21,22 The key is to optimize FM treatments and set realistic expectations prior to referral to specialists for evaluation and treatment of regional pain syndromes (for example, pain may not significantly improve after knee arthroplasty, but function likely will).
Interventions
When the APRN suggests nonpharmacologic treatments for FM to SJ, she reports being a marathon runner and exercising regularly in the past. "Now I can't evenwalk around the block without feeling achy everywhere and exhausted for days ... I know I need to exercise, but doctors don't understand that I just can't." Addressing psychological therapies, SJ asks "what will talking to a therapist do?"
The cornerstone of FM treatment is a combination of education, exercise, and pharmacologic and psychological therapies (for example, cognitive behavioral, acceptance and commitment, and operant therapies).23-25 Education is well received when it is interactive, ongoing, goal-oriented, and anchored with shared decision-making. Graded exercise is essential for maintaining physical function and reducing certain symptoms. Though patients often necessitate a combination of nonpharmacologic and pharmacologic therapies; nonpharmacologic interventions, like education, graded exercise, or psychological therapies, have fewer associated harms and safety parameters to monitor. For providers that desire to learn specific self-management techniques, several web-based resources exist that providers and patients can use together, including The Oregon Health Authority Mood and Mindset program, The University of Michigan Fibro Guide Self Care Module, and the 2021 American Chronic Pain Association-Stanford Resource Guide to Chronic Pain Management.26-28
Education
One of the Standards of Practice for Nurse Practitioners states: "The nurse practitioner provides health and wellness education and utilizes community resource opportunities for the individual and/or family."29 Patient education should play an integral role in the patient-provider relationship.
When the APRN discusses the differential diagnosis of FM with SJ, she states that other providers and specialists have mentioned FM as an explanation for her symptoms. "I've heard: 'You should exercise,' and 'There's nothing I can do for you.'"
The APRN metaphorically describes central sensitization to SJ like the volume setting on a stereo: in FM, the stereo is blaring, resulting in pain amplification and sensitivity to stimuli.
Patients may differ widely on a continuum by how much they are engulfed or dominated by FM symptoms or are able to maintain a positive view of themselves and their activity levels and quality of life, despite having FM.30 Recommendations will depend on such an assessment. Patients consumed by FM have higher FIQR scores, more depression, lower optimism, and poorer quality of life. It is important to reassure patients that FM is a legitimate disease, which is neither progressive nor fully explained by peripheral tissue damage.31 Psychotherapy should identify and reinforce activities and self-perceptions to engage patients, and thereby restore senses of self-control, self-efficacy, and self-worth.
Psychological therapies
Psychological therapies seek to change negative thoughts, introduce behavior modification, and improve coping.24,25 Additionally, they can relieve pain (by 50% or more), improve health-related quality of life (by 20% or more), and reduce negative mood and disability (by 50% or more).24,25 Also, promising trials show benefits of psychological therapies in children and adolescents.32
Cognitive behavioral therapies are not widely available, nor consistently covered by health insurance; however, COVID-19 has ushered in technology-based platforms that may expand access and overcome barriers. Though FM is sometimes mistaken as a somatic symptom disorder, psychological therapies should not be limited to individuals with severe comorbid anxiety or depression.33
Exercise therapies
APRNs should validate concerns from patients like SJ about their pain with movement. It is important to emphasize that pain is not equivalent to harm; some pain or discomfort can be normalized as likely to occur with new movements (not an injury); short-term goals may be set; and patients can be coached on their journey, celebrating small successes along the way.
Establishing the ideal prescription for exercise requires an individualized approach with anticipatory trial-and-error by the patient and provider. Once a routine is established, exercise significantly improves physical functioning, select FM symptoms, overall mood, and quality of life. Physical function improves prior to the improvement of FM symptoms, so it is important to encourage patients to focus on what they can do more easily after establishing an exercise regimen-such as, rise from a chair, stand longer, reach higher, walk farther, or carry groceries. Pragmatic advice regarding exercise for patients with FM can be shared with a physical therapist or personal trainer (see Exercise interventions for FM).34
Complementary and alternative therapies
As many patients with FM turn to integrative or complementary and alternative medicine, APRNs should be knowledgeable about the safety and efficacy of such therapies and prevent potential harm. Strong evidence supports hydrotherapy and acupuncture, and small studies support massage, relaxation, biofeedback, and mindfulness.23,35-39 Herbs, nutraceuticals, reiki, homeopathy, magnetic field, and phytotherapies are not generally recommended in part because herbs and nutraceuticals may be contaminated with toxins, arsenic, mercury, and microorganisms.23,40
Pharmacologic therapies
SJ reports taking acetaminophen and NSAIDs for the past decade. She has taken skeletal muscle relaxants and analgesics for chronic pain, and antidepressants and hypnotics for depression and insomnia symptoms. None have given her adequate relief. A 2-week course of duloxetine 60 mg daily caused nausea.
Pharmacotherapies with the greatest evidence for treating FM are antiepileptic drugs and certain classes of antidepressants, though the strength of evidence is weak overall (see Pharmacologic management).23,41 Medication initiation and management should be individualized and integrated with nonpharmacologic interventions.23 In order to individualize management, APRNs should target therapy for dominant characteristics of FM (for example, chronic pain), but also comorbidities (for example, depression, anxiety, insomnia).3,42
Though beneficial for acute pain, NSAIDs, skeletal muscle relaxants, corticosteroids, and long-term opioids are ineffective for daily use in treating chronic FM symptoms.23 Long-term opioids can worsen chronic pain symptoms through further central sensitization, and pose risks like dependence and overdose.16,23,43 If opioids are prescribed, the lowest effective dose should be used to reduce associated harms-the CDC recommends careful risk and benefit assessment when considering prescribing doses of 50 morphine milligram equivalents (MME) per day or higher and avoiding doses of 90 MME/day or higher.44
Evidence exists of efficacy of cannabinoids for chronic pain, especially if concentrated with cannabidiol (CBD), though the amount of pain relief is modest; furthermore, no standard doses, routes, frequencies, or safety profiles for cannabis are established.45 Before discussing cannabis for FM, APRNs should review institutional, local, and state policies, and abide by scope-of-practice standards.
SJ's knee exam is unremarkable, and X-ray shows mild arthritis. Following discussion, a trial of low-dose duloxetine and referral to physical therapy for FM are prescribed. SJ will follow up in 6-8 weeks.
Follow-Up
FM is a chronic health condition prone to exacerbations, and APRNs must ensure high-quality, patient-centered care through reassessment every 6-8 weeks following introduction of new treatments. The FIQR helps investigate predominant FM features, and tracks initial and follow-up status of patient symptoms (for example, pain, fatigue, sleep disturbance). APRNs should monitor for signs or symptoms not consistent with FM, like abnormal constitutional symptoms (unintended weight changes, fever, chills, night sweats, new or changing night pain), progressive worsening of symptoms, severe stiffness for more than an hour, joint hypermobility or synovitis, skin rashes or nodules, or neurologic sensorimotor deficits.4 Isolated psychiatric symptoms (for example, depression, anxiety) are not diagnostic of FM, though patients with FM may exhibit a depressed or anxious mood. APRNs should not overlook a patient having FM along with depression or anxiety. Unusual patient symptoms or abnormal physical findings other than or in addition to FM symptoms necessitate further investigation and/or specialist referral.
SJ reports improvements in widespread pain, but ongoing knee pain 6 weeks later. She is no longer "tender" when her cat sits on her lap, and water while showering no longer hurts her skin. SJ reported mild nausea for the first week after starting duloxetine, but this has subsided. Physical therapy initially worsened her pain, but following gentle, frequent exercise, she tolerates activity better without exacerbating pain. She also reports improvement in her mood and sensitivity to light. Today, her FIQR score decreased from 80 to 65.
Because her knee pain has persisted, a shared decision is made to consult orthopedics. Iforthopedic surgery is warranted, SJ is in a more optimal position to respond to therapieswithout an FM flare. Also planned is follow-up with the APRN and ongoing customization of medical care.
CONCLUSION
APRNs commonly encounter patients with FM. A step-wise, pragmatic approach to ruling in rather than ruling out diagnosis is imperative in improving patients' function and well-being, as well as reducing unnecessary specialty referrals and procedures.
REFERENCES