New-onset chronic musculoskeletal pain following COVID-19 infection fulfil the Fibromyalgia clinical syndrome criteria

BackgroundNew-onset chronic musculoskeletal (MSK) pain (> 3 months duration) is one of the commonest persistent symptoms of Post-COVID syndrome (PCS). There is emerging evidence that the chronic MSK pain and associated symptoms in PCS have similarities to Fibromyalgia Syndrome (FMS). This study aimed to characterise PCS related new-onset chronic MSK pain and its overlap with Fibromyalgia Syndrome (FMS). MethodsPatients with new-onset chronic MSK pain following COVID-19 infection were enrolled and the nature of pain and associated symptoms captured using the C19-YRS (Yorkshire Rehabilitation Scale). FMS assessment was conducted as part of standard clinical examination using the American College of Rheumatology (ACR) 2010 criteria. Diagnosis of FMS was made when they meet the standard criteria of (1) Widespread Pain Index (WPI) [≥] 7 and Symptoms Severity (SS) score [≥] 5, or WPI is 3-6 and SS score [≥] 9, (2) symptoms have been present at a similar level for at least 3 months, and (3) the patient does not have a disorder that would otherwise explain the symptoms. ResultsEighteen patients, twelve of whom were female, with an average age of 49.6 (SD 11.8) years and a Body Mass Index of 31.7 (SD 8.6) were enrolled. The average duration of symptoms from COVID-19 infection to assessment was 27.9 (SD 6.97) months. The new-onset chronic pain was widespread, primarily manifesting as muscle pain. Thirteen (72.2%) patients met the diagnostic criteria for FMS, with an average WPI score of 8.8 and an average SS score of 8.2, indicating a high level of pain and significant adverse impact on their quality of life. ConclusionThe study found that 72.2% of the patients with new-onset chronic MSK pain following COVID-19 infection met the criteria for FMS. These findings support the hypothesis that FMS may develop as a long-term sequela of a viral infection, underscoring the need for further research into post-viral long-term conditions.