Fibromyalgia Associated Pain: 2010/2011 Fibromyalgia Criteria
Fibromyalgia (FM) or fibromyalgia syndrome (FMS) induces pain all over the body, especially affecting the muscles or the soft tissue joints. As per the American College of Rheumatology (ACR) 2010 preliminary diagnostic criteria and its 2011 modification, widespread pain is no longer essential for FM diagnosis, although its deprivation may be of concern. It was examined, whether the widespread pain definition was satisfactory and the outcomes of having a small number of painful regions or of not satisfying the widespread pain criterion.
For this purpose, 5011 patients were studied who fulfilled the 2011 criteria. FM was recognized via the Widespread Pain Index (WPI) and the Symptom Severity Scale (SSS): WPI ≥ 7 and SSS ≥ 5 or WPI 3–6 and SSS ≥ 9. As per the 1990 ACR FM criteria, widespread pain was 4 quadrants plus axial pain.
The results showed that 4700 patients (93.8%) satisfied the ACR 1990 widespread pain criterion. An altered widespread pain criterion requiring 4 of 5 regions identified 98.8% of criteria-positive patients using a recent strict definition for 5 pain regions based on the WPI sites. Milder FM and no evidence of increased psychological or physical distress was observed in patients without widespread pain or those in the low WPI/high SSS group.
Mostly, in clinical and epidemiological studies, 2011 and 2010 criteria work well, but are not as beneficial in patients with asymmetrical or regional pain who do not fulfill a widespread pain criterion.
A ≥ 4-pain region widespread pain definition will identify 98.8% of current 2011 cases and abolish regional pain false-positives. Incorporation of ≥ 4-region requirement to avoid misclassification should be considered in the future revisions of the 2010/2011 criteria.