Key Facts

Fibromyalgia is a real condition with demonstrable neurobiological abnormalities in pain processing. It is not 'all in the mind' but requires a biopsychosocial management approach.

Epidemiology

• UK prevalence: 2-4%
• F:M 6-9:1
• Peak onset: 30-50 years
• Common in rheumatology clinics (15-20% of referrals)

Pathophysiology

• Central sensitisation: augmented pain processing in spinal cord and brain
• Reduced descending inhibitory pain modulation (serotonin, noradrenaline pathways)
• Elevated substance P in cerebrospinal fluid
• Abnormal functional MRI: increased activation of pain-processing regions
• Sleep architecture disruption: alpha-wave intrusion into stage 4 (deep) sleep
• Neuroendocrine: HPA axis dysregulation, low growth hormone
• Risk factors: genetic predisposition, physical/emotional trauma, chronic stress, other chronic pain conditions

Core Features

• Widespread pain: both sides of body, above and below waist, axial involvement; described as aching, burning, shooting
• Fatigue: often profound; not relieved by rest
• Sleep disturbance: unrefreshing sleep, difficulty falling/staying asleep
• Cognitive dysfunction ('fibro fog'): difficulty concentrating, poor memory, word-finding difficulty

Associated Symptoms

• Headaches (tension-type, migraine)
• IBS (abdominal pain, bloating, altered bowel habit)
• TMJ pain
• Paraesthesiae
• Morning stiffness (not prolonged as in inflammatory arthritis)
• Dizziness
• Depression and anxiety (>50%)
• Sensitivity to noise, light, temperature

Examination

• No objective joint swelling or inflammation
• Widespread tenderness to palpation
• Normal neurological examination
• Normal joint examination (may have some tender points)

Red Flags (Suggesting Alternative Diagnosis)

• True joint swelling → inflammatory arthritis
• Significant weight loss → malignancy, endocrine disease
• True muscle weakness → myopathy
• Abnormal blood tests → investigate further
• Progressive neurological signs → MS, neuropathy

Investigations to Exclude Other Diagnoses

• FBC: normal (exclude anaemia)
• ESR/CRP: normal (exclude inflammatory conditions)
• TFTs: normal (exclude hypothyroidism)
• CK: normal (exclude myopathy)
• Calcium, vitamin D: exclude deficiency
• HbA1c: exclude diabetes
• Coeliac screen (tTG): if GI symptoms

NOT Required

• Routine X-rays or MRI (unless specific indication)
• ANA, RF (unless clinical features of autoimmune disease)
• Repeated investigations → reinforce illness behaviour

Diagnosis

• ACR 2010/2016 criteria: WPI ≥7 + SSS ≥5 (or WPI 4-6 + SSS ≥9); symptoms present ≥3 months; no other explanation
• Clinical diagnosis: widespread pain + fatigue + sleep disturbance + cognitive symptoms + normal investigations

Non-pharmacological (Most Important)

• Graded aerobic exercise: most effective intervention; start low, increase gradually (swimming, walking, cycling)
• CBT: addresses catastrophising, pacing, coping strategies
• Patient education: understanding the condition, self-management (Versus Arthritis resources)
• Sleep hygiene: regular sleep schedule, avoid caffeine/screens before bed
• Mindfulness/relaxation: stress reduction
• Hydrotherapy: warm water exercise

Pharmacological

• Amitriptyline 10-25mg nocte: first-line; improves pain, sleep, and mood (NICE)
• Duloxetine 30-60mg OD: SNRI; for pain and comorbid depression/anxiety
• Pregabalin 150-300mg/day: for pain; α2δ ligand (gabapentinoid)
• Gabapentin: alternative to pregabalin
• Cyclobenzaprine: muscle relaxant (less used in UK)
• Tramadol: may be used cautiously for severe pain (some guidelines); avoid long-term

NOT Recommended

• Strong opioids (morphine, fentanyl): no evidence of benefit; significant harm (dependence, hyperalgesia)
• NSAIDs: minimal benefit in fibromyalgia (no peripheral inflammation)
• Corticosteroids: no role
• Benzodiazepines: avoid (dependence, worsens fatigue)

Multidisciplinary Approach

• Pain management programme: most effective model
• Physiotherapy, psychology, occupational therapy
• Self-management programmes

Referral Criteria

• Diagnostic uncertainty → rheumatology (one-off assessment)
• Severe, refractory symptoms → pain management team
• Significant psychological comorbidity → psychology/psychiatry

• Chronic condition with fluctuating symptoms
• No excess mortality associated with fibromyalgia itself
• 50-60% of patients report significant improvement with multidisciplinary management
• Exercise: most consistent evidence for sustained benefit
• Functional outcomes: variable; many patients maintain employment and function
• Factors associated with poorer outcomes: high catastrophising, low self-efficacy, comorbid mental health conditions, opioid use
• Spontaneous remission: uncommon but possible (~25% over 10 years)

ACR 2010 Fibromyalgia Criteria

Widespread Pain Index (WPI): Count of 19 body areas with pain (range 0-19) Symptom Severity Scale (SSS): Fatigue + unrefreshing sleep + cognitive symptoms (0-3 each) + headaches, abdominal pain, depression (0-3)

Fibromyalgia if: (WPI ≥7 AND SSS ≥5) OR (WPI 4-6 AND SSS ≥9); symptoms ≥3 months; no other disorder explaining pain

Pharmacological Comparison