Why Rheumatologists Should Know About Nociplastic Pain

Abstract

The story of nociplastic pain in rheumatology practice begins with fibromyalgia (FM). More than three decades ago, rheumatologists played a leading role in establishing criteria for FM, with early criteria requiring examination of tender points. With increasing knowledge that FM encompassed more than pain alone, along with evidence that the tender point examination showed poor reliability, the American College of Rheumatology developed updated criteria. These updates eliminated tender point assessment and instead incorporated the concept that FM was a syndrome that included “central” symptoms of fatigue, unrefreshed sleep, and cognitive dysfunction, as well as associated conditions such as headaches, abdominal pain, and depression. At that time, the concept of pain sensitization as an explanation for “invisible pain” was being actively studied by basic scientists, but had not yet translated into the clinical domain. The wide range of subjective symptoms experienced by patients with FM were difficult to explain, with many believing that symptoms were exaggerated or primarily psychiatric in origin. With growing recognition, it is now understood that nervous system sensitization is a plausible explanation for “invisible” pain that cannot be sufficiently explained by tissue abnormality. This mechanism is now identified as nociplastic pain, the third pain phenotype alongside nociceptive and neuropathic pain. Nociplastic pain is common and often unrecognized in patients with rheumatic diseases (Table 1).