A Systematic Scoping Review and Conceptual Analysis of New-Onset Fibromyalgia Manifestations After Non-Hospitalized COVID-19: Empirics, Definitions, Methodologies, Pathophysiology, Mapping of Literature, and Knowledge Gaps

This systematic scoping review examines the emergence of new-onset fibromyalgia manifestations following non-hospitalized COVID-19, highlighting the overlap with Long/Post Covid-19 syndrome (LC), chronic fatigue syndrome, and fibromyalgia. The review includes 228 records and identifies inconsistencies in definitions and methodologies, leading to a fragmented understanding of the relationship between SARS-CoV-2 infection and LC. Despite ongoing prevalence studies, the molecular mechanisms remain unclear, with conflicting findings on viral particles, central sensitization, and autoantibodies. The review emphasizes the need for standardized definitions, rigorous methodologies, and epidemiological studies to improve understanding and develop effective therapies. It proposes an integrative mechanism for fibromyalgia and LC as a non-autoimmune connective tissue disease, offering testable predictions for future research.