Panniculitis is inflammation of the subcutaneous fat that can result from multiple causes. Diagnosis is by clinical evaluation and biopsy. Treatment depends on the cause.
(See also Erythema Nodosum.)
Panniculitis can be classified as lobular or septal depending on the principal site of the inflammation within the fat.
Etiology of Panniculitis
There are multiple causes of panniculitis, including
Infections
Inflammatory disorders (eg, erythema nodosum, lipodermatosclerosis, polyarteritis nodosa)
Physical factors (eg, cold, trauma)
Lymphoproliferative disorders (eg, T-cell lymphoma)
Systemic rheumatic disorders (eg, systemic lupus erythematosus, systemic sclerosis)
Pancreatic disorders (eg, acute and chronic pancreatitis, pancreatic carcinoma)
Symptoms and Signs of Panniculitis
Panniculitis is characterized by tender and erythematous to violaceous subcutaneous nodules located over the extremities and sometimes over the posterior thorax, abdominal area, breasts, face, or buttocks. Rarely, nodules can involve the mesentery, lungs, scrotum, and cranium.
Signs of systemic inflammation, such as fever and malaise, can accompany panniculitis.
Diagnosis of Panniculitis
Clinical evaluation
Excisional or incisional biopsy
Diagnosis of panniculitis is by usually by clinical appearance and can be confirmed by biopsy.
Treatment of Panniculitis
Supportive care
Anti-inflammatory medications
Immunosuppressants
Corticosteroids (1 to 2 mg/kg orally or IV once a day) and other immunosuppressive or chemotherapeutic agents have been used to treat patients with progressive symptoms or signs of systemic involvement.
Key Points
Causes of panniculitis can vary widely.
Diagnose panniculitis by clinical evaluation (including presence of tender, erythematous, subcutaneous nodules) and confirm with excisional or incisional biopsy.
Treat panniculitis supportively and consider anti-inflammatory or immunosuppressive pharmacotherapy, particularly if manifestations are severe.
