Studies aimed at defining standardized diagnostic guidelines for each condition are urgently needed to overcome this limitation.
The review study, “Fibromyalgia and myofascial pain syndrome: Two sides of the same coin? A scoping review to determine the lexicon of the current diagnostic criteria,” was published in Muscoloskeletal Care.
Fibromyalgia and MPS are two of the most commonly diagnosed chronic muscle pain disorders. While fibromyalgia is characterized by widespread muscle pain and palpable tender points, MPS normally affects only one group of muscles and is associated with motor and sensory impairments.
One of the hallmarks of MPS is the presence of myofascial trigger points, which are small, painful nodules located within muscle fibers. In some cases, these trigger points may resemble the tender points associated with fibromyalgia, leading “to the misdiagnosis of MPS as [fibromyalgia].”
The study team said that “improper diagnosis of either condition results in a host of negative repercussions, including unnecessary medical tests and referrals, lack of symptom improvement, prolonged time to diagnose, patient frustration and an increased burden on the healthcare delivery system.”
Therefore, identifying and defining precise diagnostic guidelines for each disorder is crucial to ensure an accurate patient diagnosis and optimal care.
The review study focused on comparing the diagnostic criteria currently used for fibromyalgia and MPS in order to spot inconsistencies and overlapping guidelines that could impair the distinction between the disorders.
The review included 493 intervention studies — 410 on fibromyalgia and 83 on MPS — published between 1997 and 2017.
Regarding fibromyalgia, most intervention studies (81.7%) used the American College of Rheumatology (ACR) 1990 diagnostic criteria and, to a lesser extent, the most recent versions of the guidelines defined by the ACR.
“Out of the 410 included FM studies, all versions of the ACR criteria were cited 371 times (90.5%), as well as being indirectly cited three times (0.7%),” the researchers stated. “The ACR criteria were clearly the primary diagnostic criteria used, and the substitution of a different symptomatic duration, pain scale or recruitment method was variable, albeit the list of additional criteria was not nearly as exhaustive as that of MPS.”
Most studies (32.5%) used “The Trigger Point Manual,” defined in the 1980s as a primary source of diagnostic criteria for MPS. Additional sources of published guidelines were described in 33.7% of the studies.
In general, the diagnostic criteria used for MPS were more inconsistent compared to those used for fibromyalgia.
“Misdiagnosis is a pertinent issue in the field of chronic musculoskeletal pain, with significant repercussions on patient management. In order to rectify this issue, consistency and uniformity in
the distinction and diagnosis of either condition should be adopted by researchers and practitioners,” the investigators said.
“Future research should aim to develop a standardized vocabulary to be employed, in addition to developing consistent criteria to diagnose patients with chronic musculoskeletal pain properly,” they concluded.