Panniculitis is inflammation of the fat layer beneath the skin.

Panniculitis can develop in people with certain infections, injuries, and autoimmune disorders.

Typical symptoms include tender, red bumps under the skin.

The diagnosis is based on the person''s symptoms and often a biopsy.

There is no specific treatment, but doctors may give drugs to relieve symptoms.

The cause of panniculitis is not known, but it can develop in people with infections, exposure to cold temperature, injury, systemic lupus erythematosus, disorders of the pancreas, inflammatory disorders (such as inflammatory bowel disease and polyarteritis nodosa), and alpha-1 antitrypsin deficiency. Erythema nodosum is a type of panniculitis.