Pain in systemic lupus erythematosus: emerging insights and paradigms.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by protean clinical manifestations that are associated with immune system dysregulation. Of these manifestations, pain and pain-related symptoms such as fatigue, mood disturbance and cognitive impairment are the most common features reported by patients and represent important determinants of quality of life. Nevertheless, the relationship of these symptoms to underlying immune mechanisms is unclear. To advance scientific study and patient-centric care, this Review will consider the origin of pain in SLE and the clinical ramifications. Although many of the inflammatory aspects of SLE, including arthritis, serositis and skin disease, can be associated with nociceptive pain, patients frequently report pain that seems out of proportion to the degree of inflammation. In many of these patients, pain might reflect central and peripheral nervous system sensitization that mediates nociplasticity, a change in brain processing; with nociplasticity, changes in neuronal function and brain connections can amplify the experience of pain and pain-related symptoms. The close interplay between the immune and the nervous systems means that widespread pain and the associated symptoms can be considered as essential features of SLE; these features might share pathogenic mechanisms with other autoimmune diseases and nociplastic pain syndromes such as fibromyalgia.