Septal panniculitis

Septal Panniculitis is a type of panniculitis that primarily affects the septa within the subcutaneous fat layer. This condition is characterized by inflammation of the septa, the fibrous partitions that separate the lobules of fat in the subcutaneous tissue. Septal panniculitis can lead to various clinical manifestations, including tender skin nodules and systemic symptoms in more severe cases. It is important to differentiate septal panniculitis from lobular panniculitis, as the treatment and prognosis may differ.

Etiology

The exact cause of septal panniculitis is often idiopathic, meaning it arises without a known cause. However, it can be associated with underlying conditions such as:

• Erythema nodosum, the most common form of septal panniculitis, which is often related to infections, medications, or autoimmune diseases.
• Sarcoidosis, a systemic condition that can present with septal panniculitis among its cutaneous manifestations.
• Lupus panniculitis (Lupus profundus), associated with systemic lupus erythematosus, affecting the deeper layers of the skin.

Clinical Presentation

Patients with septal panniculitis typically present with:

• Erythematous, tender nodules, primarily located on the lower legs, though they can appear on any part of the body.
• Systemic symptoms such as fever, malaise, and joint pain may accompany the skin manifestations, especially in erythema nodosum.

Diagnosis

Diagnosis of septal panniculitis involves a combination of clinical evaluation and histopathological examination. A biopsy of the affected tissue is crucial for distinguishing septal from lobular panniculitis. Histologically, septal panniculitis shows inflammation confined to the septa without involvement of the fat lobules.

Treatment

Treatment of septal panniculitis focuses on managing the underlying cause, if identified, and symptomatic relief. Options include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) for pain and inflammation.
• Corticosteroids, either topically or systemically, to reduce inflammation.
• Potassium iodide and colchicine are also used in the treatment of erythema nodosum.
• Management of any underlying conditions, such as antibiotics for infections or specific therapies for autoimmune diseases.

Prognosis

The prognosis for septal panniculitis is generally good, especially in cases of erythema nodosum, which often resolves without long-term complications. However, the outcome can vary depending on the underlying cause and the presence of associated systemic diseases.

See Also

• Panniculitis
• Erythema Nodosum
• Sarcoidosis
• Systemic Lupus Erythematosus