Differential diagnosis between fibromyalgia syndrome and myofascial pain syndrome

Introduction. Fibromyalgia syndrome (FMS) and myofascial pain syndrome (MFPS) can be ranked among disease entities being difficult to diagnose clinically, manifesting themselves mainly through pain in specific hypersensitivity points. Aim. To present the current state of medical knowledge about pain spots appearing on hypersensitive points of soft tissue in the context of selected disease entities. Summary of the knowledge. MFPS is defined as sensory, motor and autonomic complaints, caused by the occurrence of trigger points (TrP). Yet the FMS is stated during the anamnesis on the basis of generalized pain, and pressure achiness of at least 11 out of 18 tender points (TP) of precisely determined location. Patients with FMS report numerous additional complaints – apart from the above mentioned ones; these are however highly non-specific and are not confirmed during routine medical check-ups. There are also no laboratory tests that can confirm presence of TrP being characteristic to MFPS and differentiating it from other muscles’ disease entities. Such points are identified only with the use of palpation. Unfortunately while examining a patient this way TrP – being symptoms of MFPS – can be quite easily confused with TP – being symptoms of FMS. Patients with MFPS which is developing in consequence of long-lasting global disorder of muscle tension balance and sensitivity of nociceptors as a result of chronically remaining pain, frequently suffer from achiness fulfilling the criteria of generalized pain. Moreover – in effect of static overload of soft tissues (especially of tonic muscles) – there occur hypersensitive palpable areas (points). Stimulating them cause lively reaction of the patient. Described symptoms can suggest a suspicion of FMS – the more so that making a diagnosis of MFPS does not exclude its coexistence. Having this in mind, there is a pretty large group of authors who raise a supposition that the differential diagnosis between TrP and TP should be observed in the quantitative rather than in the qualitative categories, despite the still binding definition and nomenclature. Recapitulation. Looking at the MFPS and at the FMS from the perspective of evolution of knowledge about them and from the point of view of period when scientific researches were conducted and their results published, it must be stated that during last years a considerable progress has been obtained in scope of better understanding of pathogenesis and pathophysiology of pain in specified points of soft tissue hypersensitivity, and the parallel clinical studies – confirming the hypotheses that were made – clearly increased the diagnostic and therapeutic capabilities of clinical practice.