Unidad de Reumatología, Hospital Universidad del Norte, Barranquilla, Calle 30, Vía al aeropuerto, Al lado del Parque Mundi, Colombia, Sur América
Correspondence to: C. V. Caballero-Uribe. E-mail: carvica{at}etb.net.co
SIR, I read with interest the article by Hazemeijer and Rasker on fibromyalgia and the therapeutic domain [1] and the recent editorial comments by Harth and Nielson [2] and Wolfe [3]. Controversy about fibromyalgia as a real or false disease is frequent. Recently, an article on fibromyalgia in an Amish community by White and Thompson [4] had four accompanying editorials and points of views from Gordon, Ehrlich, Hadler, and again Wolfe [58]. I have also had the opportunity to read the recent articles by Gracely et al. [9] and Paiva et al. [10] and the editorial by Crofford and Clauw in a recent journal [11].
After a more than a decade of ACR criteria, controversies remain. Is fibromyalgia syndrome (FMS) really a disease? If it is, is it a rheumatological disease or a psychiatric or psychological disease? Are the current criteria useful? Moreover, is there something useful for these patients?
FMS is a costly disease, which represents an economic problem for health care systems. Although chronic pain has always existed, since we started labeling it as FMS using the ACR criteria, work disability payments have grown up to 25.3% in developed countries [12, 13]. From my Latin American point of view, economic matters is one of the main reasons why, in developed countries, the rheumatological community is looking desperately for a cause and a marker for chronic widespread pain. Doctors need to justify diagnosis and disability in patients to the health care system and insurance companies in order for them to cover the costs of the disease. The Amish community is known for their absence of economic influences. High prevalence of FMS (7%) in this population attempts to prove that the disease develops independently from economic matters [4]. However, the controversy is still open. Current candidates for disease markers could be the substance P level in the cerebrospinal fluid [14], neurohormonal alterations [15], dysautonomic dysfunctions [16], altered alpha sleep characteristics [17] and functional magnetic resonance imaging [18], which offers interesting data but incomplete or circumstantial explanations for disease.
Furthermore, there is strong evidence that previous features of somatization contribute to the development of chronic widespread pain, and persons with FMS exhibit functional impairment, high levels of some lifetime and current psychiatric disorders, and significant psychological distress [18] labelling FMS as a mind disease with rheumatic complaints, as Hazemeijer and Rasker point out in their philosophical study [1].
Current criteria take into account only the expression (tender points) and not the causes of pain. It is well known that pain can arise from the involvement of peripheral nerve fibres but also can arise from central nerve fibres. In the 1960s, Ronald Melzac proposed a gate theory whereby physical conditions (damage extension or an inappropriate level of activity), emotional conditions (anxiety or depression) and mental conditions (boredom or subjects who are focused in pain) can open the pain gate. On the other hand, medicines or physical therapy (heat or cold), positive emotions or relaxation, an adequate level of mental concentration, extreme distraction or interest in daily activities can close the gate that modulates pain. This model posits that the brain possesses a neural network that consists of pathways linking the thalamus, cortex and limbic system, termed the neuromatrix, which integrates multiple inputs to generate patterns of neural activity. These inputs include multiple sources of afferent input, pathological input (injured nerves), endocrine, immune and autonomic system activity, medullary descending activity, CNS plasticity, attention, and psychosocial and health status factors. Therefore, any factor that alters the function of pain transmission or pain modulation pathways in the neuromatrix will influence pain perception and pain behaviour [19]. It is clear that there are several pathways of pain in rheumatic diseases, and FMS could be a natural model to explain centrally mediated pain in these diseases; neuromatrix is a conceptual framework, in addition to the therapeutic domain. In research on FMS, it would be therefore be reasonable to include patients with the different subtypes or the entire spectrum of disease rather than just those with the ACR criteria.
In the mestizo patients of Columbia, FMS is a highly recognizable disease with clinical and psychological outcomes as reported worldwide [20, 21]. In our country it is very infrequent to have a conflict of interest or legal issues because of an FMS diagnosis. FMS is still poorly recognized by the health care system and by professionals other than rheumatologists. In our setting, disability benefits paid by the healthcare system or insurance companies are as yet infrequent. Until now, we have found useful the label of FMS, since it doesn't represent an economic connotation or secondary gain and can help the patients to understand the disease.
In our experience, and according to the current evidence-based treatment of FMS [22]; FMS is a difficult clinical problem with lack of adequate treatments. Our approach to the management of patients includes an analogy of the algorithm treatment of rheumatoid arthritis proposed by the American College of Rheumatology [23]. In this analogy the initial evaluation must include a clinical examination (tender point count) and an assessment of the patient's functional and psychological status with an assessment questionnaire (Fibromyalgia Impact Questionnaire) [24]. Patient education is very important as well as indicating physical and occupational therapy and asking questions about sleep patterns before medications. Follow up management should be done. Further referrals will be done according status and response. Most drugs with acceptable evidence to treat FMS act by blocking central pain mechanisms and psychological or psychiatric evaluation is very important in some stages of disease. We find, as in RA refractory patients or resistant fibromyalgia and, of course, real psychiatric patients but, according to Crofford and Clauw [11], most patients will find quicker, better answers and hope from interested rheumatologists than other specialists.
Finally, it is important for the rheumatological community to recognize what our patients need. In a quality of life assessment [13] patients reported to need more support (52.3%), better-educated health professionals (50%), and people to believe that this disease does exist (30%). Surprisingly, issues such as better medications (15.2%), more funding for research (13.6%) or better diagnostic tools (7.6%) scored low [25].
After more than 10 yr of the ACR criteria, the current conclusion seems to be that we still lack conclusive empirical and biological evidence and we need to know more about central pain in FMS, as well as in other rheumatic diseases, and about our patients. Independently of the causes of psychological or physical widespread pain and of subsets of patients, the fibromyalgia problem may be that persistent rheumatic complaints put this syndrome for ever in the rheumatologist's agenda, andlike it or notwe need a better understanding of chronic pain mechanisms if we are to face it.
The author has declared no conflicts of interest.
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