Suprised at reading someone had been given the diagnosis "inflammatory fibromyalgia", I did a research-search on that and found a study from 2015 & a review from 2017 (by the same persons), thinking about there perhaps being a “new category” and an “inflammatory subgroup” of fibromyalgia, iFM, characterized by cytokines & other inflammatory markers/indicators: positive ESR, CRP, ANA and RF, without developing anything autoimmune.
However 1 very large survey study (53k; 1125 with FM) interestingly found that the significantly higher mean CRP "may be explained, in part," with obesity/higher IBM and co-morbidities . (Similarly a case report from 2019 for CRP & ESR.)
No other studies that cited these except one article pro-iFM from 2019 by one person had anything relevant, so this has remained an outsider hypothesis.
2015: Inflammatory Fibromyalgia: Is it Real? (& here) and
both around Samy Metyas and Daniel Arkfeld
2019: Myalgia with Elevated Inflammatory Markers in an Obese Young Female: Fibromyalgia or Polymyalgia Rheumatica?
Amongst other articles citing these, I found interesting
Italy, 2019: The juvenile *fibromyalgia syndrome (JFMS): a poorly defined disorder -* ah, some think young people having it is different?
Israel, 2021: Juvenile *primary Fibromyalgia Syndrome (JPFS) -* can’t see differences in the abstract (" subjective joint swelling" mentioned)
India, 2021: Machine Learning (i.e. Artificial Intelligence) as opposed to traditional statistical analysis showed that the CVD (cardiovascular) risk is higher in FM.
Saudi Arabia 2021: Pharmacy students & professionals were esp. likely to have FM, caused (apart from the ‘normal’ reasons) by higher working hours …