Fibromyalgia Flashcards
What is fibromyalgia?
Fibromyalgia is a chronic pain disorder.
The cause of fibromyalgia is unknown, but there is some evidence for a genetic predisposition, abnormalities in the stress response system or hypothalamic-pituitary axis, and possible triggering events.
Which gender is fibromyalgia most common in?
Women are 10 times more commonly affected than men.
What is the usual age of presentation of fibromyalgia?
Usual age of presentation is 20-50 years but it has been diagnosed in children, adolescents and older people.
What is the pathophysiology of fibromyalgia?
The exact pathophysiology is not known. Hypotheses include: -Peripheral and central hyperexcitability at spinal or brainstem level. -Altered pain perception. -Somatisation.
The nociceptive system has links with the stress regulating, immune and sleep systems which may explain some of the clinical features.
Genetic and environmental factors may play a role in fibromyalgia as it is more common in the relatives of affected patients.
What is central sensitisation?
One relatively well known theory is that of ‘central sensitisation’.
This suggests that nociceptor inputs can trigger a prolonged but reversible increase in the excitability and synaptic efficacy of neurons in central nociceptive pathways, this is the phenomenon of central sensitisation.
This then manifests as pain hypersensitivity, particularly dynamic tactile allodynia.
What is parallel processing?
Another is ‘parallel processing’. This theory hypothesises that psychosocial factor interfere with the perception of pain,
What are the risk factors for fibromyalgia?
Low household income
Lack of further education
Female sex
Family history of fibromyalgia
Having been through a traumatic event (e.g. a car crash)
Having certain conditions such as rheumatoid arthritis.
What are the main clinical features of fibromyalgia?
Symptoms of fibromyalgia are chronic widespread pain associated with unrefreshing sleep and tiredness.
Fibromyalgia is not a diagnosis of exclusion and often occurs in patients with other conditions, such as inflammatory arthritis and osteoarthritis.
The cardinal feature of fibromyalgia is chronic widespread pain. To be chronic it must be >3 month in duration. To be widespread it must be found on both sides of the body (right and left), above and below the waist and along the axial spine.
Difficulty sleeping and poor concentration/memory are also typical features.
How does fibromyalgia present?
Pain at multiple sites. Low back pain with/without radiation to the buttocks and legs and pain in the neck and across the shoulders are common complaints. Patients may complain of “pain all over”.
Fatigue.
Sleep disturbance (sleep may exacerbate symptoms and contribute to depression).
Morning stiffness.
Paraesthesiae.
Feeling of swollen joints (with no objective swelling).
Problems with cognition (eg, memory disturbance, difficulty with word finding).
Headaches (may be migrainous).
Light-headedness or dizziness.
Fluctuations in weight.
Anxiety and depression.
Symptoms are generally reported as worse in cold, humid weather and under times of stress.
How is fibromyalgia diagnosed?
This is clinical. The American College of Rheumatology has produced classification criteria for fibromyalgia. However, these criteria are not meant to be used for diagnosis.
Features include:
- 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) as shown in the diagram.
- 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.
Routine blood testing can help to exclude other differential diagnoses: eg, ESR, TFTs, antinuclear antibodies. However, be careful not to over-investigate.
What is the criteria for diagnosis of fibromyalgia?
Widespread pain index (WPI) and symptom severity score (SSS) • WPI≥7andSSS≥5OR WPI4-6andSSS≥9
Generalized pain: pain in 4/5 regions
Symptoms present ≥ 3 months
The fibromyalgia diagnosis can now be made irrespective of other diagnoses (you do not need to rule out all other conditions that could explain the symptoms, if criteria 1-3 are all met).
What are the associated conditions of fibromyalgia?
Generalised anxiety. Depression. Irritable bowel syndrome. Irritable bladder. Dysmenorrhoea. Premenstrual syndrome. Restless legs syndrome. Non-cardiac chest pain. Temporomandibular joint pain. Raynaud's phenomenon. Sicca syndrome (dryness of the eyes, mouth and other body parts). Rheumatoid arthritis: approximately 25% of patients with rheumatoid arthritis also have fibromyalgia. Systemic lupus erythematosus (SLE): approximately 50% of patients with SLE also have fibromyalgia.
What are the differentials of fibromyalgia?
Chronic fatigue syndrome. Hypothyroidism. Polymyalgia rheumatica. Inflammatory and metabolic myopathies. Polymyositis.
What are the investigations for fibromyalgia?
Patients with fibromyalgia do not have characteristic or consistent abnormalities on laboratory testing.
However, routine laboratory and imaging studies are important to help rule out diseases with similar manifestations and to assist in diagnosis of certain inflammatory diseases that frequently coexist with fibromyalgia.
The following limited evaluation is reasonable:
- Thyroid-stimulating hormone: Hypothyroidism shares many clinical features with fibromyalgia, especially diffuse muscle pain and fatigue
- 25-Hydroxy vitamin D level: Low levels can cause muscle pain and tenderness
- Vitamin B-12 level: Very low levels can cause pain and fatigue
- Iron studies including iron, total iron binding capacity, percent saturation, and serum ferritin: Low levels can cause fatigue and can lead to poor sleep and depressive symptoms
- Magnesium: Low levels can lead to muscle spasms, which are common in fibromyalgia patients;
- ESR/ CRP: usually normal in fibromyalgia and would be raised in other inflammatory arthritis.
- CK- useful if there is muscle pain, would be elevated in myositis (expect proximal muscle pain and weakness and early morning stiffness) or statin induced myopathy
- Other tests may be guided by the history for example if there are features suggestive of inflammatory arthritis or connective tissue disease include ANA, RF and anti-CCP antibodies.
What is the management of fibromyalgia?
The aim of treatment is not to cure fibromyalgia but to reduce symptoms and improve quality of life. Individual drugs are often ineffective or cause side-effects so it is important to consider a change in drug or a switch to non-drug approaches – e.g., cognitive behavioural therapy or exercise.
Pain and function should be assessed in a psychosocial context.
A multidisciplinary approach to treatment should be used. GPs, rheumatologists, physicians experienced in dealing with chronic pain, psychologists, psychiatrists, physiotherapists, etc, may all need to be involved.
Treatments should be discussed with the patient and tailored to their individual needs, including pain levels, function and associated features such as depression, fatigue and sleep disturbance.
