Pain without inflammation in rheumatic diseases.

Chronic pain is a common symptom in rheumatic diseases, and the patient with pain and no signs of inflammation poses a challenge to the physician. Notably, all rheumatic diseases have components of non-inflammatory pain and a higher prevalence of fibromyalgia compared to the overall population. Hypothetically, a chronic pain stimulus may have stronger impact in a chronic inflammatory state, and the process towards a pain condition may be influenced by individual predisposition for development of chronic pain. In addition, the features of peripheral and central pain processing may be exacerbated by inflammation, and disturbed pain processing may be a feature contributing to widespread pain. We herein review and describe the prevalence of chronic pain and different pain modalities in the most common rheumatic diseases. In addition, the background mechanisms of non-inflammatory pain in rheumatic diseases are discussed. Finally, we here review the current strategies for pain management, with a special focus on non-inflammatory pain. The key message is that pain management should be individualized and based on a thorough pain analysis with investigation of the pain modality, localization and pain intensity. Other factors to consider are the underlying rheumatic disease and treatment, the patient's mental and physical health status and psychological factors.