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. Signs and symptoms
Panniculitis can also be classified based on the presence or absence of systemic symptoms. Panniculitis without systemic disease can be a result of trauma or cold. Panniculitis with systemic disease can be caused by:

connective tissue disorders such as lupus erythematosus or scleroderma;
lymphoproliferative disease such as lymphoma or histiocytosis;
pancreatitis or pancreatic cancer;
sarcoidosis with cutaneous involvement (seen in up to 20 percent);
Alpha 1-antitrypsin deficiency
Crohns diseaseThis is not a complete list of possible causes. Associated conditions
Lipoatrophy or lipodystrophy (the loss of subcutaneous adipose tissue) can occur in any of these conditions.
: 492 
Sclerema neonatorum, affecting premature births. : 492 
Weber–Christian disease, a symmetrical form of the disease of unknown origin occurring in middle-aged women. : 492 
Lupus erythematosus panniculitis, panniculitis associated with lupus erythematosus. Forms associated with use of high doses of systemic corticosteroids during rapid corticosteroid withdrawal, and from the injection of silicone or mineral oils. : 492

Septal
Erythema nodosum
Erythema nodosum is a form of panniculitis characterised by tender red nodules, 1–10 cm, associated with systemic symptoms including fever, malaise, and joint pain. Nodules may become bluish-purple, yellowing, and green, and subside over a period of 2–6 weeks without ulcerating or scarring. Erythema nodosum is associated with infections, including Hepatitis C, EBV and tuberculosis, Crohns disease and sarcoidosis, pregnancy, medications including sulfonamides, and some cancers, including Non-Hodgkin lymphoma and pancreatic cancer. A1AT-deficiency-associated
Alpha-1 antitrypsin deficiency panniculitis is a panniculitis associated with a deficiency of the α1-antitrypsin enzyme. : 494

Treatment
See also
Panniculus carnosus
List of cutaneous conditions

References
External links
DermNet dermal-infiltrative/panniculitisDermAtlas -639418194