DESTIN, FLA. — The tender-point criteria commonly used to diagnose fibromyalgia are not useful and in fact may even explain why the disease appears to disproportionately affect women, Daniel Clauw, M.D., said at a rheumatology meeting sponsored by Virginia Commonwealth University.
According to the American College of Rheumatology's 1990 classification criteria, patients must have both widespread pain and tenderness in 11 of 18 tender points to be diagnosed with fibromyalgia.
Yet “tender points merely represent areas of the body where everyone is more tender,” explained Dr. Clauw, the executive director of the Chronic Pain and Fatigue Research Center at the University of Michigan in Ann Arbor.
Fibromyalgia patients and healthy individuals were found to have different thresholds of pain in those tender points. The two groups also had different thresholds of pain in areas not thought to be tender. In addition, the cutoff of 11 out of 18 tender points is arbitrary, he said.
In the past, the disorder was considered a discrete illness with pain and focal areas of tenderness. In more recent years, fibromyalgia has been appreciated as part of a larger continuum, with many somatic symptoms and diffuse tenderness all over the body.
Study findings suggest that the number of tender points correlates better with a patient's general stress than with pain, he said.
Women are 10 times more likely to have achy and tender points, so the higher incidence of fibromyalgia among them may be due to a selection bias created by the criteria, Dr. Clauw noted.