New Diagnostic Criteria for Fibromyalgia, No Tender Points
It’s been 20 years since the American College of Rheumatology (ACR) established the first diagnostic criteria for fibromyalgia. Now the ACR has proposed new diagnostic criteria, and gone is the requirement for tender points, a factor that often proved to be a point of contention among physicians.
The National Fibromyalgia Association reports that about 10 million people in the United State have this common chronic pain condition, and an estimated 3 to 6 percent of the world’s population is affected. Although 75 to 90 percent of those with fibromyalgia are women, the syndrome also occurs in men and children of all ethnic groups. Diagnosis is typically made between the ages of 20 and 50, but because incidence of the syndrome increases with age, about 8 percent of adults 80 years and older meet the ACR criteria for fibromyalgia.
Of course, that would be according to the old criteria; it remains to be seen if and how the numbers will change should the new criteria be adopted. One significant feature of the proposed guidelines is that they “recognize that fibromyalgia is more than just body pain,” said Robert S. Katz, a rheumatologist at Rush University Medical Center and one of the criteria’s authors.
Katz believes the new criteria, which include symptoms that are common to the syndrome such as fatigue, cognitive problems (“fibrofog”), and sleep disturbances, will help physicians make a diagnosis, and “a definite diagnosis can lead to more focused and successful treatment and reducing the stress of the unknown.”
The unknown is a hallmark of fibromyalgia: its cause is unknown, there are no lab tests to detect it, the pain and fatigue have no apparent explanation, and patients typically experience many other symptoms as well, with unknown causes.
The previously established criteria for fibromyalgia require patients to have widespread pain that has lasted for at least three months in all four quadrants of the body. They must also have moderate pain and tenderness at a minimum of 11 of 18 specific tender points on the body. These criteria do not consider the other major symptoms of the syndrome, and also are not sensitive to gender differences. “The tender point test also has a gender bias because men may report widespread pain, but they generally aren’t as tender as women,” noted Katz.
The tender point factor is also problematic because many doctors do not use this test or are not checking the tender points properly. The new proposed criteria provide a more standard set of symptoms that are more reliable for diagnostic purposes.
Elimination of the tender point test has made room for a widespread pain index and a symptom severity scale. The pain index involves use of a checklist of 19 specified areas on the body where patients can report whether they have felt pain in those locations within the last week.
Symptom severity is determined using a rating scale of zero to three, with three being the most severe. Patients will rate the three most common symptoms besides pain--fatigue, waking unrefreshed, and cognitive symptoms—and can rate other symptoms such as dizziness, irritable bowel syndrome, and depression as well.
Based on the proposed criteria, a diagnosis of fibromyalgia would be made if a patient had seven or more pain area and symptoms severity score of five or higher; or three to six pain areas and a symptom severity score of nine or higher. The new criteria still require that the symptoms be present for at last three months and that there is no other condition that could explain the patient’s pain.
Over the past 20 years, scientists and clinicians have come to know more about fibromyalgia, although the syndrome still remains somewhat mysterious. The new proposed diagnostic criteria are a reflection of the shift in understanding about fibromyalgia and will hopefully, if adopted, enhance the ability of physicians to make an accurate diagnosis and begin patients on an effective treatment program.
National Fibromyalgia Association
Wolfe F et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptoms severity. Arthritis Care & Research 2010 May; 62(5): 600