What is the initial treatment approach for panniculitis?

Initial Treatment Approach for Panniculitis

The initial treatment of panniculitis must be directed by the underlying etiology identified through deep excisional biopsy and comprehensive workup, with alpha-1 antitrypsin deficiency testing mandatory in all severe cases before initiating therapy. 1, 2

Diagnostic Confirmation Before Treatment

• Obtain a deep excisional biopsy with adequate subcutaneous tissue, not a superficial punch biopsy, as this is the most common diagnostic error that leads to missed pathology in medium-sized dermal vessels 1, 2
• Test all patients with severe panniculitis for alpha-1 antitrypsin (AAT) deficiency, particularly in necrotizing or factitious presentations, as this requires specific augmentation therapy 1, 2
• Rule out systemic causes including vasculitis, malignancy, inflammatory bowel disease, and pancreatic disorders through targeted laboratory and imaging studies 1, 2

Etiology-Specific Initial Treatment

Alpha-1 Antitrypsin Deficiency-Associated Panniculitis

Augmentation therapy with purified human AAT or fresh frozen plasma is the most effective first-line treatment, as it restores both plasma and local tissue AAT levels 1

• Dapsone may be used alone in less severe cases or combined with augmentation therapy 1
• Implement antismoking counseling and family screening as essential management components 1
• Liver transplantation achieves permanent cure in severe cases by restoring plasma AAT levels 1

Vasculitis-Associated Panniculitis (Polyarteritis Nodosa with Cutaneous Involvement)

Initiate treatment with intravenous pulse methylprednisolone 500-1000 mg/day for 3 days in severe disease, then transition to oral prednisone 0.5-1 mg/kg/day (maximum 60-80 mg/day in adults) combined with cyclophosphamide 1, 3

• For less severe presentations, start with oral prednisone 0.5-1 mg/kg/day combined with cyclophosphamide 1, 3
• In patients unable to tolerate cyclophosphamide, substitute other non-glucocorticoid immunosuppressive agents 1
• Taper glucocorticoids to 15-20 mg/day within 2-3 months to minimize infection risk, which is a leading cause of death in the first year 3

Malignancy-Associated Panniculitis

Treatment must address both the hemophagocytic lymphohistiocytosis (HLH) and the underlying neoplasm simultaneously or sequentially 1

• Cyclosporin A has demonstrated efficacy in clonal cytophagic histiocytic panniculitis and subcutaneous panniculitis-like T-cell lymphoma with HLH features 4, 1
• Etoposide-containing regimens may treat both the HLH and underlying lymphoma when present 4

Idiopathic or Undifferentiated Panniculitis

Systemic corticosteroids combined with steroid-sparing immunosuppressants represent the initial approach when specific etiology cannot be established 5

• One case series demonstrated successful treatment with systemic corticosteroids combined with methotrexate and thalidomide for 2 months, achieving complete resolution without scarring 5
• This combination approach balances efficacy with the need to minimize long-term glucocorticoid exposure 5

Critical Pitfalls to Avoid

• Never assume idiopathic disease without comprehensive workup including AAT deficiency testing, as specific etiologies require targeted therapy rather than empiric immunosuppression 2
• Do not use superficial biopsies—they miss critical pathology and delay appropriate treatment 1, 2
• Implement bone protection therapy immediately for all patients starting prolonged glucocorticoid treatment 3
• Monitor closely for glucocorticoid-related infections, particularly in the first year, as these are a leading cause of mortality 3
• Panniculitis can be lethal when associated with complications such as cirrhosis or emphysema in AAT deficiency 1

Monitoring Requirements

• Perform follow-up abdominal vascular imaging for patients with severe panniculitis and abdominal involvement who become clinically asymptomatic 1
• Use serial neurologic examinations rather than repeated electromyography for patients developing peripheral motor neuropathy 1
• Do not hesitate to repeat skin biopsy if the diagnosis remains unclear or the patient fails to respond to initial treatment 6