Limb-Threatening Arterial Thrombosis in a Patient with Eosinophilic Granulomatosis with Polyangiitis

Eosinophilic granulomatosis (EGPA), or Churg-Strauss syndrome, is a rare and necrotizing systemic vasculitis, which affects small-to-medium-sized vessels and often manifests with severe asthma and eosinophilia. We report a case of a 72 year-old male with a two-year lung-biopsy proven history of EGPA who presented with retiform purpura and patchy necrosis on his bilateral shins, which progressed to sharply demarcated, stellate ulcerations with surrounding erythema within two weeks. Laboratory work up revealed elevated anti-Cardiolipin IgM, rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein, although P-neutrophil cytoplasmic antibody (P-ANCA) and C-neutrophil cytoplasmic antibody (C-ANCA) were negative. Vascular studies revealed long anterior tibial and dorsalis pedis artery occlusion and severe small vessel disease in plantar digital arteries. Despite treatment with intravenous cyclophosphamide, pulse-dose methylprednisolone, and pentoxifylline, the patient experienced disease progression and limb threatening arterial thrombosis. This case highlights the importance of vascular and neuropathic sequelae that may result from untreated or undertreated EGPA in P-ANCA-negative patients without active pulmonary symptoms.