Idiopathic nodular panniculitis usually begins gradually. Abnormal Bumps or masses (nodules) appear in the fatty layer under the skin (subcutaneous fat) of the legs, thighs and buttocks. In some patients, the arms, abdomen, and/or face may be involved. These Nodules are usually 1-2 centimeters wide and may be either painful and tender or painless. In some patients, the affected area may become blue and red (erythema), ulcerated (open sore with yellow discharge) and waste away (atrophic), eventually healing and leaving a slight depression after a few weeks.
Another common finding associated with idiopathic nodular panniculitis is recurrent episodes of fever. Additional symptoms include a general feeling of ill health (malaise), fatigue, muscle Pain (myalgia), Joint Pain (arthralgia) and/or abdominal pain. In some patients, Weight loss may occur and Nausea may be present. Rarely, Inflammation of skin near the eye (orbital inflammation) may result in abnormal protrusion of the eye (proptosis).
In some patients, Inflammation of the subcutaneous layer of fat (panniculitis) may affect additional organ systems of the body (systemic), potentially resulting in blood abnormalities such as low levels of circulating red blood cells (anemia), liver involvement such as an abnormally large liver (hepatomegaly), Inflammation of blood vessels (vasculitis), sore muscles and joints (polyarthralgia and polymyalgia), piercing of the bowels (perforation) and lung involvement such as accumulation of fluid in the membrane surrounding the lungs (pleural effusion). These systemic events can be life threatening.