Are painful skin lesions with bleeding in a patient with Lupus and ANCA (Antineutrophil Cytoplasmic Antibody) vasculitis overlap, currently in renal remission and on Wysolone (Prednisone) and MMF (Mycophenolate Mofetil), a manifestation of vasculitis or a side effect of steroids?

Vasculitis Relapse Assessment and Management

These painful skin lesions with bleeding are most likely a manifestation of active vasculitis relapse, not steroid-induced purpura, and your decision to increase prednisone to 30 mg daily is appropriate as an initial step, but you must also optimize the MMF dose and consider reinduction therapy with rituximab. 1

Why This is Vasculitis, Not Steroid Side Effects

• Palpable purpura is the most vasculitis-specific skin lesion in ANCA-associated vasculitis, and painful skin lesions strongly suggest active small-vessel vasculitis rather than steroid-induced ecchymoses 2, 1
• Skin involvement presents as palpable purpura or infiltrated erythema indicating dermal small-vessel vasculitis in ANCA-associated conditions 1
• Steroid-induced purpura (ecchymoses and petechiae) from the FDA label is typically painless, occurs on sun-exposed areas and sites of minor trauma, and is associated with skin atrophy—not the painful, inflammatory lesions you describe 3
• At 5 mg prednisone daily, the risk of significant steroid-induced purpura is minimal, as this is within the recommended maintenance dose range for AAV in remission 1

Critical Diagnostic Workup Required Immediately

• Check ANCA titers (MPO and PR3) to evaluate serologic activity 1
• Perform urinalysis with microscopy to look for signs of renal relapse (hematuria, red cell casts, proteinuria) even though she is currently in "renal remission" 1
• Measure serum creatinine and inflammatory markers (CRP, ESR) to assess systemic activity 1
• Strongly consider skin biopsy of an active lesion—while underutilized, it is diagnostic in 68-94% of AAV cases and can show vasculitis and/or granulomatous infiltrates 4, 5

Major Treatment Problem: Subtherapeutic MMF Dosing

Your patient is on MMF 500 mg twice daily (1000 mg/day total), which is only HALF the recommended dose and substantially increases relapse risk. 1

• The KDIGO 2024 guidelines recommend MMF 2000 mg/day in divided doses (1000 mg twice daily) for AAV maintenance therapy 1
• Subtherapeutic immunosuppression is a major relapse risk factor in lupus-ANCA overlap syndromes 1
• Multiple studies demonstrate MMF at 1000 mg twice daily is effective for induction and maintenance in ANCA vasculitis with renal involvement 6, 7

Immediate Management Algorithm

Step 1: Glucocorticoid Management (Already Initiated)

• Your increase to prednisone 30 mg daily is appropriate for acute relapse 1
• Continue this dose until clinical improvement, then taper gradually 2

Step 2: Optimize MMF Dosing

• Increase MMF from 500 mg twice daily to 1000 mg twice daily (2000 mg/day total) immediately 1
• This addresses the subtherapeutic dosing that likely contributed to relapse

Step 3: Consider Reinduction Therapy

• If vasculitis is confirmed on workup or clinical presentation worsens, consider reinduction therapy with rituximab 2, 1
• Rituximab is preferred for relapsing disease according to KDIGO guidelines 8
• Do not wait for biopsy results if clinical presentation strongly suggests vasculitis with systemic features—start treatment immediately 1

Prognostic Significance

• Cutaneous manifestations in ANCA vasculitis are associated with more severe systemic manifestations including alveolar hemorrhage and glomerulonephritis 4
• In GPA specifically, patients with cutaneous manifestations have poorer relapse-free and overall survival 5
• The presence of painful skin lesions warrants aggressive evaluation for systemic involvement

Common Pitfalls to Avoid

• Do not attribute painful purpuric lesions to low-dose steroids—5 mg prednisone is unlikely to cause significant purpura, and steroid-induced purpura is painless 3
• Do not continue subtherapeutic MMF dosing—this is a setup for continued relapses 1
• Do not delay workup for renal involvement—"renal remission" can be lost quickly with vasculitis flares 1
• Do not assume skin-only involvement—cutaneous vasculitis often signals systemic disease activity 4, 5