diagnostic process in fibromyalgia

Last reviewed 06/2023

Diagnosis of this condition is often difficult and often missed due to the symptoms being vague and generalized.

The primary care physician should try and establish the diagnosis as soon as possible (before the conformation by a specialist) and communicate this diagnosis to the patient.

• explaining the link between poor sleep, tiredness, and pain will help patients  and  reassure them that they do not have another, more severe illness, such as inflammatory arthritis or cancer
• furthermore it will avoid lengthy, costly and unnecessary investigations

Fibromyalgia is not a diagnosis of exclusion. Most physicians rely on a combination of symptoms and normal blood testing to diagnose FM with less than 10% using criteria (1)

• a history of physical and mental health, with attention to the patient's psychosocial context since it may influence the expression of the disease
• physical examination should be carried out in all patients
• findings may be completely normal
• according to the ACR 2010 guidelines, specific tender point count is no longer required for a diagnosis of FM
• clinical features of a specific autoimmune disease such as inflamed joints, photosensitive rash or Raynaud's syndrome etc may be present
• only limited laboratory testing should be conducted for most patients
• e.g. urea and electrolyte, liver function test, calcium, phosphate, CRP and ESR (all normal in fibromyalgia)
•  any additional laboratory or radiographic testing should be determined by the clinical evaluation in an individual patient that may suggest some other medical condition e.g -  autoantibody test (ANA RhF etc) (even if tests shows another diagnosis the patient can have a diagnosis of fibromyalgia in addition)

Reference:

• (1) Fitzcharles MA et al. 2012 Canadian Guidelines for the diagnosis and management of fibromyalgia syndrome: executive summary. Pain Res Manag. 2013;18(3):119-26. 
• (2) Fitzcharles MA  et al. Fibromyalgia: evolving concepts over the past 2 decades. CMAJ. 2013;185(13):E645-51
• (3) Rahman A, Underwood M, Carnes D. Fibromyalgia. BMJ. 2014;348:g1224