Fibromyalgia

Question 1

What is the epidemiology of fibromyalgia?

Answer 1

Typical age of onset 20-50yrs

M:F = 1:10

Common and underdiagnosed

Question 2

What is the aetiopathophysiology of fibromyalgia?

Answer 2

Unknown aetiology

Risk factors:

• Failing to complete education
• Low income
• Female sex
• Being divorced
• FHx (genetic + environmental factors)

Associated with:

• Depression
• Chronic headaches
• IBS
• Chronic fatigue

Theories of pathogenesis involve aberrant functioning of peripheral and central pain processing

Question 3

How does fibromyalgia present?

Answer 3

Bilateral joint pain, but not necessarily symmetrical

• There are 18 palpation sites (9 pairs) commonly associated with this pain
• Places include - acromioclavicular joints, neck, borders of upper scapula, antecubital fossa, PSIS, posterolateral glutes etc.
• “pain all over”
• Worse with stress, cold or humid weather and activity

Morning stiffness

Parasthesia in hands and feet

Unrefreshing + disturbed sleep leading to fatigue; anxiety and depression; inflammatory or osteoarthritis may all co-exist

Problems with cognition e.g. memory disturbance, word finding difficulty

Analgesia is generally ineffective

Question 4

How do you investigate fibromyalgia?

Answer 4

Not a diagnosis of exclusion as there exists a classification criteria:

• Widespread pain involving both sides of the body, above and below the waist as well as the axial skeletal system, for at least three months; AND
• The presence of 11 tender points among the nine pairs of specified sites (18 points)
• Digital palpation using the thumb should be carried out to assess tenderness at these sites. The pressure applied should be just enough to blanch the examiner’s thumbnail (approximately 4 kg/cm2): in someone without fibromyalgia, this would not be enough pressure to cause pain
• These criteria are NOT DIAGNOSTIC but highly suggestive and should caution clinicians against over-investigating

Full psychosocial Hx

Some other tests are warranted however:

Bloods:
- FBC, U+E, CRP/ESR, TFTs, anti-nuclear antibodies etc. - to exclude other disorders

Question 5

How do you manage fibromyalgia?

Answer 5

MDT:
- GPs, rheumatologists, physicians experienced in dealing with chronic pain, psychologists, psychiatrists, physiotherapists

Validation:

• The patient often has waited a while for Dx and people might not understand what is going on for them, or may have been particularly dismissive in the past, blaming it solely on psychological factors
• e.g. “what you’re experiencing is real for you and it is clearly having a profound impact on your ability to cope”

Pain management:
- Can be tricky as generally not responsive to typical medications
- Tricyclics and SSRIs; venlafaxine = best SNRI (also duoloxetine), have shown to improve pain, sleep and mood,
Pregabalin + gabapentin = some evidence for
- Do not use corticosteroids or strong opioids
- CBT may be useful

Lifestyle modification:

• Management of stress and other mental health conditions
• Sleep hygiene
• Exercise - some tailored programmes exist for supervised aerobic exercise for wellbeing and fitness
• Local heat application
• Trigger avoidance