CLINICAL REVIEW Fibromyalgia Follow the link from the online version of this article to obtain certi ed continuing 1 2 3 medical education credits Anisur Rahman, Martin Underwood, Dawn Carnes 1Department of Rheumatology, Most doctors—particularly rheumatologists, pain special- SOURCES AND SELECTION CRITERIA University College London, London ists, and general practitioners—are familiar with patients We used recommendations from three current guidelines: WC1E 6JF, UK 2 who describe chronic pain all over the body, which is those from the Canadian Pain Society, the Association of Warwick Clinical Trials Unit, University of Warwick, Coventry, UK associated with a range of other symptoms including poor Scientific Medical Societies in Germany (AWMF, 2012; 3Centre for Primary Care and Public sleep, fatigue, and depression. This complex of symptoms English version www.awmf.org/leitlinien/detail/ll/041- Health, Barts and the London is sometimes referred to as fibromyalgia. Management of 004.html), and the European League Against Rheumatism School of Medicine and Dentistry, patients with this condition is often complex and challeng- (EULAR, 2008). These were supplemented by data from London, UK current Cochrane reviews and a PubMed search for ing. The diagnosis of fibromyalgia has long been controver- Correspondence to: A Rahman systematic reviews of drug treatment for fibromyalgia. We [email protected] sial, with some experts questioning whether it exists as a focused on drugs with a licence for use in the treatment of 1 Cite this as: BMJ 2014;348:g1224 separate entity. However, the symptoms and distress expe- fibromyalgia in one or more major jurisdiction or drugs that doi: 10.1136/bmj.g1224 rienced by patients with fibromyalgia are real. The causes are in widespread use for other indications. of fibromyalgia are incompletely understood, and optimal bmj.com management is compromised by the limited evidence base history of symptoms commonly seen in fibromyalgia, such Previous articles in this for the available treatments. This article reviews current as sleep disturbance and tiredness. series thinking about what fibromyalgia is, whether it is a useful For the general clinician, alternative criteria produced Ж Trigeminal neuralgia diagnosis to make, and which drugs and non-drug treat- by the ACR in 2010 may be more useful. These criteria do (BMJ 2014;348:g474) ments can be used to treat it. not require palpation of tender points. Instead patients Ж Management of are assessed by the widespread pain index—which divides traumatic amputations of What is fibromyalgia and how common is it? the body into 19 regions and scores how many regions are the upper limb In general medical practice, fibromyalgia is diagnosed in reported as painful—and a symptom severity score that (BMJ 2014;348:g255) patients with chronic widespread pain and multiple mus- assesses severity of fatigue, unrefreshing sleep, and cognitive Ж Managing wheeze in cular tender points on examination or associated symptoms symptoms. The widespread pain index and symptom sever- preschool children of fatigue, unrefreshing sleep, or cognitive dysfunction (or a ity scores have been combined into a single questionnaire (BMJ 2014;348:g15) combination thereof). Many patients have both tender points with a maximum score of 31,6 7 which can be completed by Ж Erectile dysfunction and associated symptoms. self report. Two recently published population surveys using (BMJ 2014;348:g129) Chronic widespread pain is defined in epidemiological this 31 point questionnaire found a population prevalence for studies as pain for at least three months, affecting both sides fibromyalgia of 2.1% in Germany8 and 6.4% in Minnesota, Ж Acute haematogenous 2 3 7 osteomyelitis in children of the body, both above and below the waist. Epidemiologi- USA. In the German study, a cut-off questionnaire score of cal evidence from several countries shows that it is a common 12-13 was statistically best at distinguishing those who ful- (BMJ 2014;348:g66) problem, present in about 10% of the population.3 4 Not all of filled the ACR 2010 criteria from those who did not, but there these people have fibromyalgia. The population prevalence of was no sharp division of clinical features between popula- fibromyalgia was first measured as about 2% using consen- tions above and below this score.8 The authors concluded sus classification criteria for fibromyalgia published by the that patients with fibromyalgia are not a separate discrete American College of Rheumatology (ACR) in 1990.2-5 These group but instead constitute the upper end of a continuous criteria (sensitivity 88.4%, specificity 81.1%) were simple— spectrum of polysymptomatic distress within the population.8 fibromyalgia could be diagnosed in a patient with chronic Figure 1 summarises the way in which clinical features widespread pain if at least 11 of 18 specific sites on the body can be used to diagnose fibromyalgia by general clinicians surface were tender to digital palpation. However, the tender or specialists. point test is hard to standardise, some healthy people also have tender points, and these criteria take no account of a Who gets fibromyalgia? Fibromyalgia has often been considered to affect mostly SUMMARY POINTS women. The Minnesota population survey found that 7.7% Symptoms of fibromyalgia are chronic widespread pain associated with unrefreshing sleep of women and 4.9% of men fulfilled ACR 2010 criteria for and tiredness fibromyalgia, but a parallel medical records study in the Fibromyalgia is not a diagnosis of exclusion and often occurs in patients with other same population found that only 27% of these people conditions, such as inflammatory arthritis and osteoarthritis had been diagnosed with the condition.7 Strikingly, the No clear pathophysiological mechanism for fibromyalgia has been established, but prevalence of medically diagnosed fibromyalgia was 2% evidence suggests that there is an abnormality in central pain processing in women but only 0.15% in men, a difference inconsist- Diagnosing fibromyalgia can allow the patient’s polysymptomatic distress to be explained, ent with the true population prevalence figures.7 Similarly, thereby reducing fear and doubt although most patients diagnosed in clinics are young or Fibromyalgia has no cure, but a range of drug and non-drug treatments can reduce middle aged, population surveys show clearly that the symptoms and their impact on the patient’s life prevalence rises steadily with age, with a maximum preva- Trial evidence for all forms of treatment in fibromyalgia generally shows only small to 3 7 moderate average effects lence in the over 60s. Perhaps older people with chronic widespread pain are diagnosed with osteoarthritis rather 28 BMJ | 1 MARCH 2014 | VOLUME 348 CLINICAL REVIEW to show increased glutamate and glutamine in the right How long has the pain been present? amygdala in 30 patients with fibromyalgia compared with > months < months healthy controls, but no correlation was found between these increases and clinical features of fibromyalgia.16 Is the pain widespread?* Not bromyalgia Although these changes in cerebrospinal fluid biochem- Yes No istry and cerebral signalling are associated with fibromyal- Are there clinical features of specic Not bromyalgia gia, it is unclear whether the association is causative. autoimmune diseases, such as inflamed joints, photosensitive rash, or Raynaud’s syndrome? Why and how should fibromyalgia be diagnosed? Yes No Some specialists have argued that a diagnosis of fibromyal- Urea and electrolytes, liver function tests, Simple blood tests only (urea and electrolytes, gia is unhelpful because it overmedicalises this complex of calcium, phosphate, C reactive protein, liver function tests, calcium, phosphate, C reactive distressing, medically unexplained symptoms.1 But in our erythrocyte sedimentation rate, and protein, and erythrocyte sedimentation rate) autoantibody tests (such as ANA, RhF) (all normal in bromyalgia) experience, many patients find the diagnosis helpful, espe- (all normal in bromyalgia) cially when combined with a common sense explanation Note: Even if tests show another diagnosis the patient can have a diagnosis of the link between poor sleep, tiredness, and pain. Such of bromyalgia in addition a diagnosis can reassure patients that they do not have another, more severe illness, such as inflammatory arthri- tis or cancer, thereby halting a cycle of repeated normal Are there symptoms of unrefreshing sleep, fatigue, or diculty concentrating? investigations in search of a diagnosis. This allows patients to move forward and find ways of reducing the symptoms’ Fibromyalgia impact on their lives. Palpation for muscular tender points is optional but may help validate diagnosis for patient No blood tests or imaging modalities are useful for diag- Fig 1 | Flow chart for diagnosis of fibromyalgia. ANA=antinuclear antibodies; RhF=rheumatoid nosing fibromyalgia. C reactive protein concentrations and factor. *Widespread pain defined as pain both above and below the waist and on both sides of the erythrocyte sedimentation rate are not usually raised the body (unlike in inflammatory arthritis), and joint radiographs are usually normal (unlike in osteoarthritis). The diagnosis than fibromyalgia. Fibromyalgia is not restricted to devel- of fibromyalgia is made purely on a clinical basis. Some cli- oped countries. A large study in Bangladesh (n=5211) nicians test tenderness at the 18 sites specified in the ACR involving door-to-door surveys with