Panniculitis is inflammation of the fat layer beneath the skin.
There are many causes of panniculitis. Infections are the most common causes. Other causes include cold temperatures, injury, systemic lupus erythematosus, disorders of the pancreas, and alpha1-antitrypsin deficiency. Some forms, such as a widespread form known as Weber-Christian disease, have no known cause.
Panniculitis is characterized by tender, red skin bumps (nodules). The bumps are quite deep because they are located in the layer of fat beneath the skin. They tend to be large, measuring several centimeters in diameter. The bumps can appear anywhere on the skin but are most common on the legs and arms and less often on the buttocks, trunk, and face.
People may have symptoms of general bodywide inflammation such as fever, joint and muscle pain, and feeling ill.
In Weber-Christian disease, bodywide inflammation can also cause organ dysfunction, including problems with the liver, pancreas, and bone marrow, which can be fatal.
There is no specific treatment for panniculitis.
Doctors may give nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and inflammation. Other drugs that may help somewhat include drugs that are used for malaria, dapsone, or thalidomide.
Corticosteroids and other drugs that suppress the immune system (immunosuppressants) or chemotherapy drugs may be given to people whose symptoms are getting worse. Associated conditions are also treated.