Panniculitis is a group of diseases whose hallmark is inflammation of subcutaneous fatty and muscle tissue. Symptoms include tender skin nodules, and systemic signs such as weight loss and fatigue.
The appearance of single or multiple crops of nodules in subcutaneous fat is the hallmark of acute panniculitis. The nodules are usually, but not always, tender. On occasion, they drain an oily solution and suppuration (pus) may occur. Individual lesions last from one to eight weeks before disappearing, and a pigmented depressed area may be left at the involved site.