What is the treatment for panniculitis?

Treatment of Panniculitis

Treatment of panniculitis must be guided by the underlying etiology, with deep excisional biopsy being the essential first step to establish the correct diagnosis and direct appropriate therapy. 1

Diagnostic Approach

Obtain a deep excisional biopsy reaching medium-sized vessels and adequate subcutaneous fat tissue, as superficial biopsies frequently miss the pathology and represent the most common diagnostic error. 1, 2 The specimen should be divided for:

• Histopathological evaluation to classify as septal versus lobular panniculitis and identify vasculitis 1, 3
• Microbiological culture to exclude infectious causes 3
• T-cell clonal expansion analysis if lymphoma is suspected 3

Test plasma alpha-1 antitrypsin (AAT) levels in all cases of biopsy-proven severe panniculitis, particularly those with necrotizing or ulcerative features, as this requires specific augmentation therapy. 1, 2

Etiology-Specific Treatment

Alpha-1 Antitrypsin Deficiency-Associated Panniculitis

Initiate augmentation therapy with purified human AAT or fresh frozen plasma as primary treatment, which restores plasma and local tissue AAT levels and represents the most effective intervention. 1, 2 This therapy is rational, safe, and effective for this specific etiology. 1

• Add dapsone either alone in less severe cases or combined with augmentation therapy for additional therapeutic benefit 1, 2
• Provide antismoking counseling and family screening as essential management components 1
• Consider liver transplantation in severe refractory cases, which has achieved permanent cure by restoring plasma AAT levels 1

Subcutaneous Panniculitis-Like T-Cell Lymphoma (SPTCL)

Without hemophagocytic syndrome (HPS): Initiate systemic corticosteroids or other immunosuppressive agents as first-line therapy, with 5-year survival of 91%. 4, 1 For solitary lesions, use radiotherapy. 4

With hemophagocytic syndrome: Immediately start multi-agent chemotherapy due to the aggressive nature, with 5-year survival dropping to 46%. 4, 1 This represents an extremely aggressive clinical syndrome requiring immediate intervention. 4

Vasculitis-Associated Panniculitis (Polyarteritis Nodosa)

Treat with cyclophosphamide combined with high-dose glucocorticoids for polyarteritis nodosa presenting with cutaneous panniculitis. 1

• For severe disease, initiate intravenous pulse glucocorticoids rather than high-dose oral formulations 1
• In patients unable to tolerate cyclophosphamide, substitute alternative non-glucocorticoid immunosuppressive agents 1
• Perform follow-up abdominal vascular imaging in patients with prior abdominal involvement who become clinically asymptomatic 1

Infectious Panniculitis (Nocardia)

Initiate sulfamethoxazole-trimethoprim (SMX-TMP) as first-line therapy, with alternative agents including sulfadiazine, amikacin, imipenem, meropenem, ceftriaxone, minocycline, moxifloxacin, linezolid, or dapsone. 1

• Continue treatment for 6-24 months depending on extent of dissemination and degree of immunosuppression 1
• Perform surgical debridement for necrotic nodules or large subcutaneous abscesses 1

Erythema Nodosum (Most Common Septal Panniculitis)

Provide symptomatic support alone, as erythema nodosum typically resolves without specific treatment even when no causative condition is identified. 5 The condition is self-limited in the majority of patients. 5

• Identify and treat underlying triggers including infections, drugs, sarcoidosis, inflammatory bowel disease, pregnancy, or malignancy 5
• In typical clinical presentation with bilateral pretibial nodules, skin biopsy is not required 3

Idiopathic Recurrent Panniculitis

After comprehensive workup excluding AAT deficiency, vasculitis, lupus, lymphoma, and systemic diseases:

• Use moderate-dose oral glucocorticoids (prednisone 0.25-0.5 mg/kg/day) as adjunctive therapy during acute flares 2
• Consider cyclosporin-A for refractory cases, which has demonstrated efficacy in mixed panniculitis 6
• For immunocompromised patients achieving remission, continue immunosuppressive therapy for at least 18 months 2

Monitoring Strategy

Perform serial clinical examinations focusing on new nodules, ulcerations, or systemic symptoms rather than repeated invasive procedures or imaging. 1, 2 For patients with peripheral motor neuropathy secondary to panniculitis, use serial neurologic examinations rather than repeated electromyography. 1

Critical Pitfalls to Avoid

• Inadequate biopsy depth is the most common diagnostic error—always obtain deep excisional specimens reaching subcutaneous fat and medium-sized vessels 1, 2
• Panniculitis can be lethal, especially when associated with cirrhosis or emphysema in AAT deficiency, or when associated with hemophagocytic syndrome in lymphoma 1
• Do not delay treatment in suspected hemophagocytic syndrome, as this represents a medical emergency requiring immediate multi-agent chemotherapy 4
• Always exclude malignancy-associated panniculitis, which requires treatment of both the underlying neoplasm and any associated hemophagocytic lymphohistiocytosis 1