Fibromyalgia is a condition characterised by chronic widespread musculoskeletal pain and fatigue for no apparent reason.
A commonly proposed theory suggests a form of 'central sensitisation', so that fibromyalgia patients develop a lower threshold of pain perception in the brain.
Interestingly there is increasing evidence that the brains of fibromyalgia patients actually have structural and behavioural differences when compared with those of healthy individuals. However, the exact correlations of this and the condition itself are still mostly unclear.
The prevalence of fibromyalgia might be as high as 2-7% of the general population in developed countries. It affects significantly more women than men (the ratio is at least 7:1) and may start at almost any age, although it is less common in childhood.
Patients with rheumatic diseases, such as rheumatoid arthritis or Sjogren's syndrome, often develop symptoms as in fibromyalgia, but patients with primary fibromyalgia do not seem to be at increased risk of developing another rheumatic disease or an additional neurological condition.
Fibromyalgia patients often feel significantly restricted in terms of work and everyday activities. If they reduce exercise due to the experienced pain, the condition often worsens.
2. Differential diagnoses
The most important differential diagnoses are inflammatory, autoimmune and thyroid disorders or rheumatological conditions as mentioned above. Sometimes depression or psychiatric conditions and deliberate malingering for secondary gain need to be excluded.
There are similarities and overlaps between chronic fatigue syndrome and fibromyalgia, although the latter has more marked physical elements.
A difficulty that patients with fibromyalgia often experience is a perceived lack of awareness and understanding among healthcare professionals regarding the condition.
Some clinicians actively disagree with the validity of the existence of fibromyalgia because there are no consistent abnormalities on physical examination, and because of the absence of available objective diagnostic tests.
This means that the journey from onset of symptoms until diagnosis can be long and frustrating for a patient and may undermine their faith and trust in medical systems.
There is no straightforward laboratory test for fibromyalgia, so the diagnosis relies mostly on the history. Many patients experience a dramatic and inflammatory type of pain and typically describe it as burning, throbbing, shooting, stabbing or ripping. Often the pain is worse in the morning and can be very disabling.
The diagnosis of fibromyalgia is likely if there is a combination of pathognomonic symptoms in all four body quadrants for longer than three months and if at least 11 out of 18 tender points defined by the American College of Rheumatology (ACR) are positively painful to pressure.
In 2010, the ACR extended and refined its 1990 diagnostic criteria for fibromyalgia to integrate more detailed elements, subtleties and new insights gained over the past 20 years.
A significant proportion of patients with fibromyalgia have additional problems such as tension headaches, features of irritable bowel syndrome or overactive bladder, sleep disorders, features of restless leg syndrome or temporomandibular joint disorder and possibly food sensitivities. These can all be challenging just by themselves and may even initially distract from reaching the underlying diagnosis.
The key to managing patients with fibromyalgia is to establish and build a meaningful working relationship - if a patient feels dismissed or fundamentally misunderstood, it can be difficult to regain their trust. It is important to do all necessary baseline tests to ensure no other likely differential diagnosis has been missed.
No detailed specialist skills or knowledge are needed to do the tender point test in a GP setting. However, a referral to rheumatology can be useful to confirm the diagnosis and to allow early access to a multidisciplinary team as available. It is important to advise the patient at some point that the condition is likely to be chronic.
Supportive medical treatment with amitriptyline and/or SSRIs can be helpful for coping with the exhaustion and emotional effects from the pain. Some patients may be at risk of developing a dependency on stronger analgesia. On the other hand, it can be unhelpful to be too categorical and too strict with effective painkillers rather than allowing the medication and closely monitoring its use. Other medications, including pregabalin and duloxetine, may be useful for some patients.
Complementary medical treatments and nutritional concepts tend to lack firm or consistent evidence. Input from physiotherapy and possibly psychology can be very valuable to enhance effective self-management.
Paced exercise and stretching are essential to reduce pain and maintain reasonable function. A commonly suggested goal to work towards gradually is five exercise sessions a week of at least 20 minutes each.
5. Referral criteria
Consider offering referral to rheumatology at diagnosis, or for confirmation of fibromyalgia when you suspect it. Although the condition and its symptoms may fluctuate to some degree, progressively worsening symptoms should trigger a rethink and a referral for a second opinion.
- Dr Jacobi is a GP in York
- Wolfe F, Clauw DJ, Fitzcharles MA et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res 2010; 62(5): 600-10. www.rheumatology.org/practice/clinical/classification/fibromyalgia/2010_ Preliminary_Diagnostic_Criteria.pdf
- Fibromyalgia Association UK www.fmauk.org
- UK Fibromyalgia www.ukfibromyalgia.com/