Fibromyalgia

Question 1

Define fibromyalgia

Answer 1

chronic pain syndrome diagnosed by the presence of widespread body pain for at least 3 months in addition to tenderness of at least 11 out of 18 designated tender point sites. Tenderness should be elicited immediately

Question 2

What are the causes/risk factors of fibromyalgia?

Answer 2

• It is not fully understood.
• The current hypothesis is that fibromyalgia is caused by aberrant peripheral and central pain processing.
• Two key factors are:
- Allodynia: Pain in response to non-painfyl stimuli.
- Hyperesthaesia: Exaggerated pain response to mildly painful stimuli.
• It is thought that there is a reduced expression of serotonin (inhibitory to the pain pathway) and an increased release of Substance P and neurogenic growth factors (propagatory in the pain pathway).
• Thus, there is a hypersensitivity to pain.
• As it often runs in families, there is a strong genetic link to fibromyalgia.

Associations:
• Other somatic syndromes such as chronic fatigue syndrome, irritable bowel syndrome and chronic headaches syndromes.
• Also found in ~25% of patients with RA, AS and SLE.

Question 3

What are the signs and symptoms of fibromyalgia?

Answer 3

• Diagnosis depends on pain that is chronic (>3months) and widespread (involves left and right sides, above and below the waist, and the axial skeleton) in the absence of inflammation; and the presence of pain on palpation of at least 11/18 ‘tender points’ –left and right:

• Suboccipital muscle insertions
• Anterior aspects of the inter-transverse spaces at C5–C7;
• Midpoint of the upper border of trapezius
• Origin of supraspinatus near the medial border of the scapular spine
• Costochondral junction of 2nd rib
• 2cm distal from lateral humeral epicondyle
• Upper outer gluteal quadrant
• Posterior to the greater trochanter
• Knee, at medial fat pad proximal to joint line

• Patients can also have:

• Morning stiffness
• Fatigue
• Depression and low mood
• Poor concentration
• Sleep dosturbances

Question 4

What investigations are carried out for fibromyalgia?

Answer 4

• Diagnosis is clinical; no diagnostic tests can confirm the disease and all investigations should be normal.
• ESR/ CRP - Normal, to exclude an inflammatory cause of pain.
• TFT - Normal, to exclude hypothyroidism as a cause of fatigue.
• FBC - Normal, to exclude anaemia as a cause of fatigue.
• Antibody Serology - Normal, to exclude any rheumatological cause of pain and tiredness.
• Vitamin D Levels - Normal, to exclude osteomalacia or rickets.