Inflammation of the subcutaneous adipose tissue.

Panniculitis is a group of diseases whose hallmark is inflammation of subcutaneous adipose tissue (the fatty layer under the skin – panniculus adiposus). Symptoms include tender skin nodules, and systemic signs such as weight loss and fatigue. Restated, an inflammatory disorder primarily localized in the subcutaneous fat is termed a "panniculitis", a group of disorders that may be challenging both for the clinician and the dermatopathologist.: 487  The general term for inflammation of any adipose tissue is steatitis..