A diagnosis of fibromyalgia is a difficult one. There’s no blood or other laboratory test, and while there are typically several presenting symptoms, few of them are objective, and there is considerable variation from person to person. Fundamentally then, it remains a diagnosis of exclusion. If nothing else is a better fit, the doctor can tick the fibromyalgia box.
Fibromyalgia diagnostic criteria
Diagnostic criteria for fibromyalgia were proposed as early as the 1970s, but it was not until 1990 that the American College of Rheumatology (ACR) published diagnostic criteria based upon the presence of eleven of eighteen tender points causing pain for at least three months. Other common symptoms of fibromyalgia were not included in these criteria, and subsequent research found that many patients who were accepted as having the syndrome did not satisfy the tender point criteria alone. In fairness to the researchers, their criteria had not been intended for use in a clinical setting. Still, the paper was seized upon by a frustrated medical profession in the absence of anything more reliable.
Eventually, in 2010 the ACR updated their criteria, which do not require the counting of tender points, with further proposals for reform published in 2011 and 2016.
What are fibromyalgia tender points?
While doctors do not know what causes them, tender point, otherwise referred to as pain points, are tender areas around joints, but not in the joints themselves. Pressure on them causes pain, which tends to be felt just beneath the skin’s surface. The most painful area of the tender point is usually small, about the size of a penny.
Tender points are typically distributed in a symmetrical pattern around the body, over the neck, back, chest, elbows, buttocks, hips, and knees. Pressing on them with sufficient force to turn a fingernail white will cause sharp pain.