Summary

What is known?
Fibromyalgia and ME/CFS are poorly understood conditions with overlapping symptoms. Complexity may have contributed to consideration of both as functional or somatic disorders. Shared symptoms have fuelled debate as to whether they are manifestations of the same spectrum or separate entities. Both are associated with hypermobility.
What is question?
What is the contribution of variants in connective tissue (eg symptomatic joint hypermobility) to chronic pain and fatigue in fibromyalgia and ME/CFS? To what degree do these conditions overlap?
What was found?
From a research perspective, fibromyalgia and ME/CFS are almost indistinguishable. Variant connective tissue is highly prevalent and frequently overlooked in fibromyalgia and ME/CFS. Aspects of hypermobility diagnostic classification, particularly historical joint laxity, predict pain and fatigue symptomatology in these conditions.
What is implication for practice now?
All physicians will be facing the challenge of assessing possible ‘post-viral fatigue’ in the wake of COVID-19. Patients presenting with pain and fatigue should be assessed for hypermobility, particularly historical joint laxity in order to help inform multidisciplinary treatment targets and consideration of known comorbidities (eg autonomic dysfunction).