Department of Internal Medicine, Rheumatology section, University of Palermo, Italy
There is still a great debate on the definition of fibromyalgia (FM) and how to deal with patients affected by this condition. Although FM has been considered a musculoskeletal disorder rather than a central sensitization syndrome, its classification is not easy since it is a systemic disease. The complexity of the symptoms reflects an intriguing pathogenesis in which the neuroimmuno axis seems to be widely involved. It is for such complexity that, in reality, we should ask whether FM is really so different from other rheumatic diseases. The crucial points is to understand which pathogenetic factors are at the base of FM, where patients report severe pain. The experience of pain is the cardinal element of the disease, making it the first element of treatment. Nowadays, the treatment of chronic pain is widely debated and new therapeutic approaches have been borrowed and made available also for FM. One of these approaches is based on the hyperbaric oxygen therapy (HBOT), which has been found able to modulate immune system response. Recent findings, in this stream of research, have demonstrated that FM patients show a significant increase in inflammatory mediators such as TNF-alpha, an activation of T helper 1 lymphocytes and a reduction of central nervous mediators such as serotonin. These alterations are correlated with widespread pain, fatigue, sleeping disorders and the quality of life. After HBOT the modulation of immune system is rapidly obtained restoring the balance of CD4+ T cell subsets and relative cytokines. CD4+ T cell subsets have significant cross-talk, with the ability to “differentiate” given appropriate environmental signals, suggesting that environmental factor could participate to the activation of immune system. These findings suggest a great involvement of immune systems in the pathogenesis of FM. The proinflammatory status detected in FM patients makes FM not so different from other rheumatic diseases in pathogenetic terms. On the contrary, the conventional treatments used for rheumatic disease appear ineffective for FM making it different in regards to therapy. The end of the pattern towards the definition of FM is still open and many other studies will be necessary to put together the pieces of a still incomplete puzzle.